Between January 1976 and June 1991, 161 women underwent restorative proctocolectomy. Seventeen (10.6 per cent) developed pouch-vaginal fistula. There was no difference in the incidence of inflammatory (15 of 141; 10.6 per cent) and non-inflammatory (two of 20; 10 per cent) disease, the severity of colitis or the number of stages in the operation. In 15 patients the fistula involved the ileoanal anastomosis; in two it had possibly occurred at the dentate line. There was no significant difference in the proportion of hand-sewn (ten of 120; 8.3 per cent) and stapled (seven of 41; 17 per cent) ileoanal anastomosis. Of the 17 women, six had pelvic sepsis in the immediate postoperative period and five had an anastomotic complication. There was no case of Crohn's disease. Three patients developed a pouch-vaginal fistula before closure of the ileostomy. The remaining 14 fistulas occurred a median of 7 (range 1-144) months after closure. Five further patients were referred from elsewhere to give a total of 22 for analysis of treatment and outcome. The fistula developed before ileostomy closure in five patients (group 1) and after closure in 17 (group 2). Following treatment, six fistulas had healed with five patients still undergoing treatment. In group 1, three of the five fistulas healed, whereas in group 2 only three of the 17 healed. Eight patients required excision of the pouch. The prognosis appears to be worse when pouch-vaginal fistula occurs after ileostomy closure. The optimal management is not yet established.