Since results from non-surgical procedures designed for treatment of chronic anal fissure are still controversial, sphincterotomy remain as the "state of the art" therapy for this condition. In a retrospective basis, the authors intend to review results from treatment of chronic anal fissure in 220 patients who underwent surgical procedure between 1984 and 1995. Data from chart review included age, sex, location of the lesion at the canal anal, associated anorectal disease, delivered surgical technique and complications. Seventy per cent of the patients were male. Mean age was 37.1 years. Fissure was located at the posterior midline in 86.1%. Associated anorectal conditions occurred in 41.4%. Fissurectomy plus posterior sphincterotomy was the treatment of choice in 84.1%. Complications occurred in 5 (2.3%) cases. There were no incontinent patients. Mean follow-up was 2.6 years. The authors conclude that partial internal anal sphincter section produces excellent results in treatment of chronic anal fissure. Posterior sphincterotomy may persist effective and safe since continence impairment was not identified in the present study.