An anal fissure is a tear in the anoderm distal to the dentate line and can be acute or chronic. Acute fissures are those that have been present less than 2 to 3 months and heal with local management. Chronic anal fissures, due to scarring and poor blood flow, often require surgical intervention due to failed conservative management. Most commonly, anal fissures occur in the posterior midline; however, in up to 25% of women and 8% of men, a fissure can be located in the anterior midline. Comparative study to obtain the best method for treatment of chronic anal fissure by comparison outcome of lateral sphincterotomy and fissurectomy with sustained digital anal dilation. This study included 100 patients admitted in general surgery department of AL-Zahraa university hospital. Demographic data was recorded to all patients including age, sex. Position of fissure. Pre-operative symptoms and signs mainly pain, bleeding. constipation, discharge and pruritis ani Laboratory investigations was done for all patients mainly PT, PC.INR. The patients in this study divided into two groups. Group A: include 50 patients was managed by fissurectomy and lateral internal sphincterotomy Group B: include 50 patients was managed by fissurectomy and digital anal dilatation all patients were followed for 6 months to assess any complications. In this study, they were 60 (60%) females and 40 (40%) males with age ranged from 18 to 66 years with mean ± SD of 36.86 ± 12.60 years. post fissure found in 85%, ant fissure found in 15% Early follow up Group A: two patients (4%) complain of bleeding,4 patients (8%) complain of infection,4 patients (8%) delayed healing ,3 patients (6%) Incontince to liquid and gases Group B:no patients complain of bleeding ,1 patient (2%) infection, no patients delayed healing, 2 patients (4%) Incontince to liquid and gases Late follow up Group A; stenosis in one patient (1%), recurrence in one patient (1%) Group B; no patient complicated by stenosis was recorded; recurrence found in one patient (1%). Both anal dilatation (AD) and Lateral internal sphincterotomy (LIS) provides early pain relief and high ulcer healing rate. However, AD appears to be safer with regard to healing and infection.