Infectious granulomatous prostatitis is uncommon, and most cases of granulomatous prostatitis are classified as nonspecific granulomatous prostatitis. From 2007 to 2009, 5 patients experienced poor wound healing after radical prostatectomy for prostate cancer at a specialist cancer center. Mycobacterium abscessus was cultured from the debridement specimens, and acid-fast-positive bacilli were identified histologically within the prostates. All 180 radical prostatectomy specimens from May 2007 to June 2009 were reviewed, and 7 additional cases with morphologies suspicious of M. abscessus granulomatous prostatitis (MAGP) were identified. The characteristic morphologic feature of MAGP was suppurative necrotizing granulomatous inflammation extensively (10% to 80% of the gland; mean, 39%) involving the prostate. The centers of MAGP were large areas of neutrophilic abscess and necrotic debris, which were surrounded by histiocytes, lymphocytes, plasma cells, scattered multinucleated giant cells, and eosinophils. In the adjacent areas, there was a lobular extension of mixed inflammatory infiltrates into dilated and ruptured ducts. Involvement of extraprostatic soft tissue and seminal vesicles/vas deferens was found in 9 and 4 cases, respectively. Acid-fast-positive bacilli were identified in 5 radical prostatectomies. Eleven patients had fresh tissue specimens stored at -150°C, and M. abscessus was cultured from 8 prostates. Random amplified polymorphic DNA-polymerase chain reaction showed the same clone for all isolates. After prostatectomy, 8 patients experienced prolonged wound healing, with urethrorectal fistula formation in 1 patient and a pelvic abscess in another. It is critical for pathologists to recognize MAGP and to distinguish it from the more common nonspecific granulomatous prostatitis and other granulomatous lesions within the prostate.