Prostate specific antigens occurs in serum in different molecular isoforms, and serum levels of these isoforms have been introduced as adjuncts for prostate disorder screening to reduce misdiagnosis. Little data exist on the use of these tests for screening patients with BPH . In the current study, serum level of total, free and complex  prostate specific antigen (tPSA,fPSAand cPSA) isoforms and serum sarcosine were evaluated in 200 BPH patients and 200 matched controls. tPSA level  was 15.13±1.15 ng/ml in BPH patients and 2.75±0.22 ng/ml in controls. fPSA was 2.81±0.16 ng/ml in BPH patients and 0.72±0.03 ng/ml in controls. cPSA was 12.31±1.05 ng/ml in BPH patients and 0.72±0.03 ng/ml in controls. Serum sarcosine was 118.70±1.80 nmol/dl in BPH patients and 64.94±0.81 nmol/dl in controls. The differences between patients and controls in all the analytes are significant (