Eleven patients with benign prostatic hypertrophy (BPH) and urinary retention requiring catheter drainage in all cases except one, were treated with either hydroxyprogesterone caproate (eight patients) or chlormadinone acetate (three patients) for 3 to 16 months continuously. Six patients voided spontaneously with less than 50 ml residual urine within three months; in two others, similar results occurred after five months of treatment. Three patients were unresponsive to therapy. Among a control group of ten patients with BPH and retention requiring catheter drainage, only two voided spontaneously with less than 50 ml residual urine after two months, a statistically significant difference from the treated group. Of eight patients responding favorably to treatment, residual urine, symptoms of prostatism, and renal function remained stable for an average follow-up of 13 months following discontinuation of therapy.