Objective: Both botox and lateral internal sfinkterotomi are treatment technics used in chronic anal fissure; provide the relaxation of anal sphincter and as a result of this, healing occurs. Aim of this study is to compare efficacy of botox and LIS treatment in chronic anal fissure and discussing with the literature. Methods: 60 of 66 patients who has chronic anal fissure, that we reached, treated but not healed with medical therapy, appealed to the Dr. Sami Ulus Hospital included the study. Gender, age, fissure localization, complaints (pain, bleeding, itching, constipation), complaint length, recurrences after treatment, continence conditions and complications of patients were registered. Results: Sixty patients were enrolled the study. Of the 60 patients; 38(63.3%) were male and 22 (27.7%) were female. Mean age of all patients was 35.93 ± 11.45 (21 -60). Pain was the common complaint of the all patients. 10 (32.3%) recurrence were detected in botox treatment group (Group-I), only 1 (3.4%) recurrence was in LIS group (Group-II). There was no complication as an incontinence in group-I but 3 cases with incontinence (10.39%) were obtained in group-II. In the evaluation of these 3 cases by Cleveland Clinic Continence Scoring System, 2 cases classified as gas incontinence and 1 case as moderate fecal incontinence. Conclusion: Although botulinum toxin injection seen as an alternative treatment method with low complication rates such as incontinence, high recurrence is an important shortcoming of this technic. LIS performed by experienced surgeons remained the most popular treatment modality with low complication rates and great deal of healing success.