A series of 121 patients with chronic fissure-in-ano who underwent fissurectomy with superficial midline sphincterotomy was studied. The mean follow-up was 8.1 years. Minor problems with anal competence occurred after the operation in 30 patients (25 per cent). Within two months, this problem had resolved in all patients. One patient (0.8 per cent) had a true recurrence. Five patients (4.1 per cent) had recurrent acute anal abrasions as the result of passage of a hard stool. These healed spontaneously. Twelve patients (9.9 per cent) had fragile scars, but this was a significant problem in only five (4.1 per cent). No patient had significant stricture formation, keyhole deformities, or major persistent problems with anal competence. The patients graded their operations with regard to satisfaction: 118 (97.5 per cent) reported satisfactory results and three (2.5 per cent) reported unsatisfactory results. This study shows that fissurectomy with superficial midline sphincterotomy is a viable approach to the surgical management of chronic fissure-in-ano.