In 70 cases of granulomatous prostatitis 54 (77%) mimicked carcinoma clinically. Granulomatous prostatitis is a distinct clinical and pathological entity, apparently a reaction to extravasated prostatic secretions into the surrounding tissues secondary to obstruction and infection within the prostate. In about 80% of the patients, there was a triad of (1) high fever followed by (2) symptoms of nonspecific prostatitis and (3) suggestion of a malignant prostate on rectal palpation. These features should suggest a presumptive diagnosis of granulomatous prostatitis, although histological confirmation is desirable. The disease occurs at a slightly earlier age than prostatic carcinoma. Empirical nonsurgical treatment will suffice in most cases if sufficient time is allowed for the inflammatory reaction to resolve. This seldom requires more than three months.