Background : R.C.C is the most common form of cancer affecting the kidney. It account for approximately 2-3% of adult malignancies as well as 2% of all cancer death . The aim of this study is to correlate between different clinicopathological variables of patients with RCC including patients age , sex tumor size , site , location , grade , stage and histopathological types with PSA expression in tumor. Patients and methods : A retrospective study of 40 cases of surgical nephrectomy diagnosed as RCC with different histological types were taken from the department of pathology of Al-Kadhemia Hospital and Teaching lab of medical city hospital for the period between May 2004 - May 2005 . All the 40 specimens obtained were processed and examined by immunohistochemical technique to detect their reactivity to PSA. Results ; Of the 40 cases which studied, there were 14 female patients (35%) and 26 male patients (65%). Age range from (20-70) years and mean age was 57.2 years and mean size of tumor was 7.5cm3.In regard to immunohistochemical results , 8 cases were stained positive for tissue PSA i.e. 20%. Majority of the positive cases were in mean age of 62.5 years and mean size of 7.8cm and most of the positive cases were of mixed type of RCC in grade II of differentiation and stage III. Conclusion:- 1 - Tissue PSA as a tumor marker is neither prostatic nor cancer specific . 2- Our study shows no significant difference between PSA tissue expression and sex whether male or female and the site of the tumor whether right or left kidney, while significant correlation in regard to the age , size of tumor, polar location , degree of differentiation , grading and histopathological subtypes was found .