OBJECTIVE Despite improvements in surgical practice, persistent perineal wound sinus is still a common complication after proctectomy. This study presents the success of a modified cleft closure technique in dealing with this problem. METHODS From May 1997 patients with a persistent perineal sinus after surgery underwent a cleft closure - similar to that performed for patients with pilonidal sinus disease. RESULTS Eight patients (6 male, 2 female) with an average age of 52 years underwent a cleft closure for a persistent perineal sinus after surgery. Four patients had undergone a proctocolectomy (ulcerative colitis), 2 an abdominoperineal excision of the rectum (adenocarcinoma) and 2 a proctectomy (1 Crohn's disease, 1 complication of diverticular disease). Symptoms had been present for an average of 41 months (range 5-152 months) and 3 patients had undergone other procedures attempted previously to deal with the problem. The first three patients had the procedure as an inpatient with an average stay of 4.7 days. The next 5 patients had the procedure as a day case (2 local anaesthetic, 3 general anaesthetic). Two patients developed a postoperative wound infection and all but one wound had healed completely by 8 weeks. In this patient the procedure was repeated to achieve healing. There was no other associated morbidity and no postoperative deaths. There have been no recurrences to date. CONCLUSIONS Modified cleft closure for persistent perineal sinus is a simple procedure with low morbidity that can be performed under local anaesthetic in the day surgery unit.