Local or regional recurrence is frequent in patients treated for rectal cancer. Many will die with regional disease in the absence of distant metastases. To achieve cure or palliation, radical surgery resulting in large pelvic defects may be warranted. Myocutaneous flap reconstruction may be used to achieve satisfactory closure. From 1988 to 1993, nine patients (5 female, 4 male) underwent 10 myocutaneous flap reconstructions for large perineal or pelvic defects following surgical extirpation of recurrent rectal cancer at Fox Chase Cancer Center. All nine patients had been previously treated with radiation therapy. Their clinical course was reviewed and quality of life assessed. The mean age at diagnosis of recurrence was 56 years. In six, this was a first, and in three patients a second recurrence. Clinical presentation was most often bleeding, abscess, or perineal pain. Resection was determined by extent of recurrence and included perineal resection, pelvic exenteration, cystectomy, sacrectomy, or coccygectomy. Extent of disease necessitated intraoperative radiation therapy in one case and placement of brachytherapy catheters in four. Bilateral gracilis flaps were used in four, unilateral in three, gluteus maximus in two, and combined gluteal and gracilis flaps in one patient. Six perineal and four combined perineal and vaginal defects were reconstructed. The mean length of surgery was 9.1 hours, and the length of hospitalization averaged 17.5 days. In nine of 10 cases, patients had prehospital level of function at discharge. Acute surgical flap-related complications included three cases of minor wound infection or separation, two of minimal but persistent drainage, and one of vaginal colonization.(ABSTRACT TRUNCATED AT 250 WORDS)