Background and Objective: Non-specific granulomatous prostatitis is an uncommon diffuse inflammatory condition of the prostate. It is important because it may be mistaken for prostatic carcinoma. The aim of the study was to determine the prevalence of non-specific granulomatous prostatitis (NSGP) and comparing the results of transrectal ultrasonography, serum prostate specific antigen (PSA) and free prostate specific antigen levels, digital rectal exam (DRE) in NSGP with the prostate carcinoma and benign prostate hyperplasia. Materials and Methods: During a cross-sectional study, the prostate needle biopsy cases with the granulomatosts prostatitis diagnosis that had been referred to one of the largest pathology centers (1 year: 2006) were found and their clinical files were revised from the point of DRE, transrectal ultrasonography (TRUS), FPSA, and PSA. Some clinical and pathology findings such as age, microscopic findings, sonography information and experimental findings that had been necessary for the study were gathered and analyzed using SPSS software. Results: Out of 783 needle biopsies of prostate, 8 (1.02%) cases were non-specific granulomatous prostatitis. The age range of patients was 55-76 years (with a mean of 66.1 years). Mean of PSA level was 19.45 ng/ml and fPSA level was 0.7 ng/ml. In 2 patients, TRUS showed focal hypoechoic areas and in other 2 of these DRE revealed asymmetry and mild nodularity. Conclusion: There is no pattern of clinical, biochemical or ultrasound findings that allows a specific diagnosis of granulomatous prostatitis to be made or differentiate it from prostatic carcinoma and the biopsy is still necessary for the certain disease diagnosis.