Objective: To compare lateral internal anal sphincterotomy with 2% diltiazem in the treatment of chronic anal fissure in terms of fissure healing and complications. STUDY DESIGN: Randomised controlled trial. PLACE & DURATION OF STUDY: Dept of general surgery, Victoria hospital, Bangalore. From June 2013 to May 2014 with a minimum follow up of 6 months. METHODOLOGY: Sixty patients were randomly assigned into two treatment groups. Group A was assigned to apply 2% diltiazem paste while, in group B lateral internal sphincterotomy (LIS) was done. Response to the treatment was assessed in terms of fissure healing, pain relief and occurrence of complications. Follow up of the patients was carried out at the end of 2nd, 4th, and 6th week of treatment. RESULTS: In group A 5 patients had healing at 2 weeks, 12 at 4 weeks, and 22 at 6 weeks. In group B 14 patients had healing of fissure after 2 weeks, 24 at 4 weeks, 27 at 6 weeks. 4 patient in group A and 3 in group B had no healing. In this study overall healing rate after 6 weeks with diltiazem was 73.33% and 90% with LIS. CONCLUSION: 2% diltiazem cream is in par with Lateral internal sphincterotomy. The need for hospital stay is abolished; psychological and financial burden on the patient is reduced. With a healing rate close to 90%, topical Diltiazem can be considered as the first line of treatment of chronic anal fissure especially in patients who are not fit or not willing for surgery.