A 76-year-old man presented with palpable omental metastasis and gross ascites due to prostate cancer. Within 3 months of surgical castration, the ascites resolved completely, the omental mass was reduced by more than 75%, and serum PSA fell to 4.24 ng/ml from 368.4 ng/ml. Worthwhile palliation can be achieved in patients with massive effusions secondary to metastatic prostate cancer using hormone manipulation.