AIM: Laying open fistulotomy is the standard treatment for simple anal fistula. However, healing of the resultant anal wound may be prolonged and may adversely affect a patient's lifestyle and work. This randomized trial aimed to assess the effect of topical phenytoin 2% powder spray on healing of the anal wound following fistulotomy. METHOD: Adult patients with simple anal fistula who underwent anal fistulotomy were divided into two equal groups: group I applied topical phenytoin 2% powder spray on the anal wound regularly with sitz baths until complete healing was confirmed clinically and group II had regular sitz baths only. The primary outcome of the study was time to complete wound healing. Secondary outcomes were postoperative pain, complications, time to return to work and impact on lifestyle. RESULTS: Sixty patients (50 of whom were men) with a mean age of 41.4 ± 12.5 years were included. Both groups had comparable pain scores at 1 week after surgery (1 ± 0.83 vs 0.86 ± 0.81; P = 0.51). The duration to complete wound healing was 41.2 ± 2.4 days in group I and 42 ± 2.5 days in group II (mean ± SD, P = 0.21). The time to return to work was 13.5 ± 2.8 days in group I and 14.1 ± 2.6 days in group II (mean ± SD, P = 0.39). No significant differences were noted between the two groups with regard to postoperative complications or impact on lifestyle. CONCLUSION: The use of topical phenytoin 2% powder spray did not promote wound healing, relieve postoperative pain or accelerate patient recovery after anal fistulotomy for simple anal fistula.