Anal fissure is a common condition, and although most are short-lived and heal spontaneously, those that persist and require intervention cause considerable morbidity in an otherwise healthy young population. Traditionally, lateral internal sphincterotomy was the gold standard treatment for chronic fissures, but this procedure is associated with a risk of incontinence to some degree in 30% of patients. The discovery of pharmacologic agents that effectively cause a chemical sphincterotomy and heal most fissures has led to approximately two thirds of patients avoiding surgery. Topical 0.2% GTN ointment probably is the most widely used first-line treatment. Other drugs currently under investigation may offer effective treatment with fewer side effects. Another advantage of these novel treatments is that by acting through different pathways, they may be effective in the 30% of cases in which GTN fails, the risks associated with surgery may be avoided. Studies of botulinum toxin injection into the anal sphincter have reported excellent healing rates, although the procedure is more invasive, and patients may find it uncomfortable and less tolerable. Chemical sphincterotomy is particularly suitable in patients with associated inflammatory bowel disease, in whom sphincterotomy for anal fissure generally is contraindicated. When pharmacologic therapy fails or fissures recur frequently and patients have raised resting anal pressure, lateral internal sphincterotomy is the surgical treatment of choice. The results are satisfactory when patients are selected carefully and the incision is limited to the length of the fissure. When chemical sphincterotomy fails and resting anal pressures are not elevated, as is commonly the case with patients developing fissures postpartum, an advancement flap should be considered.