In summary, anal fissures are a common problem that can usually be identified by an attentive history and limited physical examination. Initial management should consist of conservative, nonoperative treatments, as most fissures heal with minimal intervention. Medical options exist for treatment of chronic fissures, but none have proven to be superior to lateral internal sphincterotomy. Lateral internal sphincterotomy has been the standard treatment for chronic anal fissure, but fissure healing rates of up to 80% with topical glyceryl trinitrate (GTN) treatment have suggested that this operation may become redundant. We evaluated the results of topical treatment of chronic anal fissures with 0.2% GTN for 8 weeks in the outpatient clinical setting with the results of treatment by lateral internal sphincterotomy. GTN induced fissure healing in 10 of 20 consecutive patients after8 weeks and 14 of 20 after 13 weeks Lateral internal sphincterotomy was performed in 20 patients. At the 8-week post-sphincterotomy review, 90% of fissures had healed and 100% at 10 weeks post-sphincterotomy, there were no major complications. In this study topical GTN for treatment of chronic anal fissure in the outpatient setting was not as effective as demonstrated in controlled clinical trials. Lateral internal sphincterotomy is still a good therapeutic option, especially in patients not responding to GTN.