Hyperlipidemia is an elevated concentration of lipids in the blood. The major plasma lipids of interest are total cholesterol and the triglycerides. It is closely related to the terms hyperlipoproteinemia (elevated levels of lipoproteins). It is not a disease but a metabolic derangement that can be secondary to many diseases and can contribute too many forms of disease, most notably cardiovascular disease including myocardial infarctions (known as a heart attack, which is a disease state that occurs when the blood supply to a part of the heart is interrupted. The resulting ischemia or oxygen shortage causes damage and potential death of heart tissue). Objectives : 1.Study the effect of acute myocardial infarction on levels of total cholesterol, triglyceride, high density cholesterol, low density cholesterol, ratios total cholesterol/HDLC and LDLC/HDLC at acute phase. 2.Comparing the levels of total cholesterol, triglyceride, high density cholesterol, low density cholesterol, ratios total cholesterol/HDLC and LDLC/HDLC at 24 hours on acute myocardial infarction with day 3 after acute myocardial infarction. 3.Comparing the levels of total cholesterol, triglyceride, high density cholesterol, low density cholesterol, ratios total cholesterol/HDLC and LDLC/HDLC at 24 hours on acute myocardial infarction with day 3 after acute myocardial infarction according to pathologic levels (lower, borderline and higher) levels of risk factors for heart diseases. 4.Study the effect of acute myocardial infarction on levels total cholesterol, triglyceride, high density cholesterol, low density cholesterol, ratios total cholesterol/HDLC and LDLC/HDLC day 1 (within 24 hours) on acute myocardial infarction as comparing with day 3 after acute myocardial infarction for males and females. 5.Comparing the levels of total cholesterol, triglyceride, high density cholesterol, low density cholesterol, ratios total cholesterol/HDLC and LDLC/HDLC at 24 hours on acute myocardial infarction with day 3 after acute myocardial infarction for the patients with diabetes mellitus and hypertension that consider risk factors for heart diseases and secondary cause of lipid abnormalities. Subject and methods : The present study was designed to investigate change in serum lipid profiles in the patients with acute myocardial infarction. The present study consisted of 50 patients who were admitted to the hospital with acute myocardial infarction. Serum levels of total cholesterol, triglycerides, high density cholesterol, low density cholesterol, ratios total cholesterol/HDLC and LDLC/HDLC were determined on day 1 (within24 hours) of acute myocardial infarction and day 3 after acute myocardial infarction. Serum lipid profiles were compared between day 1 of acute myocardial infarction and day 3 after acute myocardial infarction. The measurements occur in Central Laboratories Department of Biochemistry and Coronary Care Unit in Al-Yarmook Teaching hospital. The cholesterol and triglycerides were measured by using enzymatic colorimeteric method. Assay method by Spectrophotometer. The HDLC was measurement by using HDLC Precipitant method. The LDLC was estimated by Friedewald formula. This measurement is recruited from (1/3/2007 to 15/1/2008). The study included the patients with acute myocardial infarction and excluded those patients who have liver or renal disorder, abnormal thyroid function, symptoms suggestive of acute myocardial infarction for more than 24 hours, patient had hospital stays of less than 3 days and the patients were receiving lipid-lowering drugs. Results : Serum total cholesterol, triglycerides, LDLC, ratio TC/HDLC and ratio LDLC/HDLC showed significant decrease (p<0.05) on day 1 as compared to day 3 after acute MI. HDLC showed no significant change (p>0.052) between day 1 to day 3 after acute MI. Result at pathologic values showed that total cholesterol, triglycerides, LDLC and ratio TC/HDLC decreased significantly (p<0.05) in day 1 as compared to day 3 after acute MI only at higher risk levels for heart diseases. But they showed no significant change in day 1 as compared to day 3 after acute MI at low and borderline risk levels for heart diseases. HDLC showed significant increase (p=0.03) only at borderline risk levels for heart diseases. The ratio TC/HDLC showed significant decrease day 1 as compared to day 3 after acute MI at borderline risk levels for heart diseases (p=0.039) and higher risk levels for heart diseases (p=0.008). Result in male group showed that total cholesterol, triglycerides, LDLC, and ratio TC/HDLC decreased significantly (p<0.05) on day 1 as compared to day 3 after acute MI. HDLC and ratio LDLC/HDLC showed no significant change (p>0.05) between day 1 to day 3 after acute MI. Result in female group showed that total cholesterol, LDLC, and ratios TC/HDLC and LDLC/HDLC no significant change (p>0.05) day 1 as compared to day 3 after acute MI. Triglycerides showed significant increase (p=0.033) in day 1 as compared to day 3 after acute MI but HDLC showed significant decrease (p=0.015) in day 1 as compared to day 3 after acute MI. Also result lipid profiles for females higher than in males of the same age (60±11 years). Result in patient with diabetes mellitus showed that Serum total cholesterol, triglycerides, LDLC and ratio TC/HDLC decreased significantly (p<0.05) on day 1 as compared to day 3 after acute MI. HDLC showed increased none significant (p>0.0.097) between day 1 to day 3 after acute MI. Ratio LDLC/HDLC showed none significant decrease (p=0.058) on day 1 as compared to day 3 after acute MI.Result in patient with hypertension showed that total cholesterol, triglycerides, LDLC, ratio TC/HDLC and ratio LDLC/HDLC were decreased none significant (p>0.05) on day 1 as compared to day 3 after acute MI. HDLC showed increased none significant (p=0.4) on day 1 as compared to day 3 after acute MI. There was high positive correlation coefficient between total cholesterol and triglycerides, LDLC, ratio TC/LDLC and ratio LDLC/HDLC also, high positive correlation between LDLC with ratio TC/HDLC and ratio LDLC/HDLC, also, high correlation between ratios TC/HDLC with ratio LDLC/HDLC in the patients with acute myocardial infarction. Strong negative correlation between HDLC with ratio TC/HDLC and with ratio LDLC/HDLC. Positive correlation between triglycerides with ratio TC/HDLC and with ratio LDLC/HDLC. Negative correlation between HDLC with LDLC. A weak correlate was regarded between triglycerides and LDLC, also, negative weak correlation between total cholesterol with HDLC and between triglycerides with HDLC. The results of lipid profile with BMI showed that high positive correlation BMI with total cholesterol, triglycerides, LDLC, ratio TC/HDLC and ratio LDLC/HDLC. But negative weak correlation between BMI with HDLC. The results of lipid levels with age were regarded weak correlation between age and HDLC. Also negative weak correlation between age with BMI, total cholesterol, triglycerides, LDLC, ratio TC/HDLC and ratio LDLC/HDLC. Conclusions: 1.In this study we found that acute myocardial infarction effect on lipid profiles levels only HDLC has not been affected on acute myocardial infarction but HDLC still could be useful for risk assessment in the patients with acute myocardial infarction. 2.In this study it was found that acute myocardial infarction affect on lipid profiles with higher pathologic values (higher risk levels for heart diseases) but has not been affected on the lower and borderline risk levels for heart diseases. Only HDLC has not been affected by acute myocardial infarction at higher pathologic values (higher risk levels for heart diseases) but affect at borderline risk levels. 3.This study proved that higher levels risk of lipid profiles increase risk for heart diseases. Only HDLC at higher levels was considered as protective against heart diseases. 4.In this study it was found that levels lipid profiles for females was higher than lipid profiles levels for males. 5.Acute myocardial infarction incidence in males was higher than incidence of acute myocardial infarction than in females. 6. This study was found that acute myocardial infarction affect on lipid profiles levels on the patients with diabetes mellitus but has not been affected on lipid profiles in the patients with hypertension. 7. This study proved that the patients with diabetes mellitus and hypertension increase levels of total cholesterol, triglyceride, LDLC, ratios TC/HDLC and LDLC/HDLC but decrease HDLC level .