Prostatic adenocarcinoma cells can be detected in urine cytology specimens when the tumor extends to the bladder mucosa. We report a case of prostatic adenocarcinoma diagnosed by urine cytology. A 70-year-old man presented with urinary frequency and low back pain On rectal examination, a nodular mass was palpated in the left side of prostate. Bone scan revealed multifocal hot lesions suggesting metastasis. Urine cytology revealed hypocellular smear on clean or bloody background. Tumor cells were mainly arranged in syncytial or papillary clusters which occasionally contained fool of luminal formation The cytoplasm of tumor cells was finely granular. The nuclei of tumor cells revealed evenly distributed fine chromatin and large prominent nucleoli without nuclear pleomorphism. In needle biopsy specimen of prostate, tumor cells were detected in entire prostatic tissue with extension to pericapsular soft tissue. The tumor cells infiltrated individually or in a cord-like fashion with fool of cribriform pattern. Inconspicuous nuclear pleomorphism and prominent nucleoli were also noted.