BACKGROUND: Medical treatment, including glyceryl trinitrate ointment, represents the first step for the management of chronic anal fissure. However, glyceryl trinitrate ointment is associated with headache and, consequently, a high withdrawal rate of the treatment. OBJECTIVE: The aim of the present study was to evaluate the effect of the topical application of tocopherol acetate ointment on pain relief and chronic anal fissure epithelialization, comparing it with the effect of a standard treatment with glyceryl trinitrate ointment. DESIGN: This is a 2-parallel-group, single-center, randomized controlled, intent-to-treat clinical trial. SETTINGS: This study was conducted at the Garcilaso Clinic affiliated with Universidad Alfonso X (Madrid, Spain). PATIENTS: Patients with chronic anal fissure were selected. INTERVENTIONS: Patients were randomly assigned into 2 groups: patients receiving tocopherol acetate ointment and patients receiving glyceryl trinitrate ointment. MAIN OUTCOME MEASURES: The primary end point was quantification of anal pain 8 weeks after beginning the treatment as measured by a Visual Analogue Scale ranging from 0 to 100 mm. The secondary end points were the healing rate (during the treatment period of 8 weeks) and the recurrence rate. RESULTS: One hundred sixty consecutive patients were treated, 80 in each group. By 8 weeks after treatment, mean anal pain score declined by 56.2 mm in the glyceryl trinitrate ointment group compared with a mean anal pain score decline of 67.1 mm in the tocopherol acetate ointment group (mean difference, 10.9 mm (95% CI, 4.3-18.6); p = 0.018). Sixteen weeks after finishing the therapy, the recurrence rate was 13.2% in the glyceryl trinitrate ointment group vs 2.9 in the tocopherol acetate ointment group (p = 0.031). LIMITATIONS: Limitations of the study include the absence of manometric measurements of the internal anal sphincter before and after the treatments and the use of glyceryl trinitrate ointment as an active comparator, whereas calcium channel blockers are actually the standard treatment. CONCLUSIONS: Anal pain was significantly lower in the tocopherol acetate ointment group than in the glyceryl trinitrate ointment group at 8 weeks after treatment. Tocopherol acetate ointment achieved a greater healing rate and a lower recurrence rate 16 weeks after finishing the treatment.