A 56-year-old man presented with long-standing, mild urinary frequency 6 years after radical prostatectomy. Pathologic assessment showed presence of organ confined prostate cancer (pT2a), Gleason 6 (3+3). Since the time of surgery, PSA level was undetectable and the patient remained without evidence of recurrent disease. However, digital rectal examination revealed the presence of a very large mass palpable on the anterior rectal wall. Therefore, the patient underwent abdominal/pelvic MRI which demonstrated presence of a solid, well-circumscribed pelvic mass extending from the level of the sacrum posteriorly to the anterior abdominal wall. Histologic examination of percutaneous biopsy of the mass was suggestive of schwannoma. The patient underwent laparotomic excision of the mass, which was confirmed to be a schwannoma, with its characteristic slender spill cells and elongate nuclei. No intra-operative complication was reported. The patient has no evidence of recurrence with complete resolution of urinary symptom one year after surgery.