Aiming to obtain a base line information on the lipid profile in subjects with and without coronary heart disease (CHD), to find out the impact of 12 hours over night fast on serum lipids and to study serum lipids in the offspring of premature CHD patients, a case control study was conducted during the period between December l'St 2002 and October 30th 2003 in Ibn AL Nafis hospital in Baghdad. It included 126 subjects with confirmed CHD chosen randomly every other patient (76 males and 50 females), an age and sex matched 126 subjects without CHD as controls from the attendants of the out- patient clinic and 32 offspring of premature CHD patients. The necessary information was collected from the study sample after obtaining their consent to participate in the study two blood samples were obtained from every participant, the first, one after 12 hours over night fasting and the other one within two hour after breakfast (postprandial). For the offspring a fasting sample was obtained only. Serum was tested for glucose and for serum lipids using the enzymatic methods. The mean serum cholesterol was significantly higher in cases than in controls while that for HDL cholesterol was significantly lower. Distribution of hyperlipidemia according to the body mass index (BMI) revealed that hyperlipidemia was present even in those with BMI 25 kg/m2. The mean level of different types of serum lipids was higher in subjects with central obesity except for HDL cholesterol which was lower. Significant differences and high correlation were found between the means of different serum lipids in fasting and postprandial states except for HDL cholesterol when there was no significant difference. But on utilizing the National Cholesterol Education Program Classification, the most prevalent dyslipidemia identified was the low level of serum HDL cholesterol which accounts about 63.5% of CHD patients and 72.2% of the controls. The distribution of subjects and their controls into dbe desirable, border line and undesirable groups in both fasting and post prandial states showed no significant difference. The study of the offspring of premature CHD patients revealed that 6S.~5:» oflbem have different type of dyslipidemia. 53.1% of them with high .evel of serum total cholesterol. Females had higher level of serum lipids than males and there was no significant difference among parents and their offspring as regard different type of serum lipids except for HDL cholesterol. in conclusion the study has shown that there was no significant difference in the distribution of different types of dyslipidemia between fasteing and postprandial states, in spite the fact that there was significant difference between the mean level of fasting and post prandial serum lipids. Dyslipidemia was very common in the offspring of premature CHD yet, there was no significant difference between the frequency of these abnormalities aong parents and their offspring. Mechanism underlining the events mentioned in this study has been fully discussed.