OBJECTIVE To assess the utility of gracilis muscle transposition in the treatment of iatrogenic rectourethral fistula. BACKGROUND Iatrogenic rectourethral fistula poses a rare but challenging complication of treatment for prostate cancer. A variety of procedures have been described to treat this condition, none of which has gained acceptance as the procedure of choice. The aim of this study was to review the authors' experience with gracilis muscle transposition in the treatment of iatrogenic rectourethral fistula. METHODS A retrospective chart review of all patients who underwent gracilis muscle transposition for iatrogenic rectourethral fistula was performed, and follow-up was established by telephone interview. Successful repair was defined as absence of a fistula after reversal of fecal and urinary diversions. RESULTS Eleven men, mean age of 62 years, underwent 12 gracilis muscle transpositions for rectourethral fistula between 1996 and 2001. Six patients had a history of pelvic radiotherapy, and five patients had previous failed attempts to repair the fistula. In nine patients, the fistula healed following gracilis muscle transposition. One patient developed a rectocutaneous fistula that healed with fibrin glue injection, and one developed perineal sepsis requiring debridement of the transposed gracilis. This patient underwent a second gracilis transposition, which uneventfully healed. Overall, all of the patients had closure of their diverting stomas and maintained healed rectourethral fistulas. There were no intraoperative complications, and the only long-term complication of this procedure was mild medial thigh numbness in two patients. CONCLUSIONS Gracilis muscle transposition is an effective surgical treatment for iatrogenic rectourethral fistula. It is associated with low morbidity and a high success rate.