This study was aimed to demonstrate the significance of free/total Prostate Specific Antigen (PSA) ratio in the diagnosis of prostatic enlargement. The study was carried out in a total number of tOo subjects, of which 58 had benign prostatic hyperplasia (BPH), 42 had cal’cinoma prostate and 50 were age matched control. The subjects were collected from Dhaka Medical Collegc Hospital (DMCH) and Bangabandhu Sheikh Mujib Medical University (BSMMU). Venous blood (5ml) was drawn from each subject before digital rectal examination or pre-urethral manipulation for estimation of PSA. Final diagnosis was made by histopathological examination, specimen being obtained by transurethral resection of prostate (TURP), open prostatectomy and per rectal tru-cut biopsy with biopsy gun.