Aim — to objectify the criteria for choosing the method of treatment of anal fissures, to determine the indications for surgery and sphincterotomy. Material and methods. The results of treatment of 206 patients with chronic and acute anal fissures between the ages of 17 to 75 years are analyzed. The posterior anal fissure was detected in 175 (84.9%) patients, the front — in 18 (8.7%), the combination of fissures was noted 13 (6.3%) times. The history of the disease — from 1 month to 12 years. The examination included analysis of clinical data, indicators of pre- and postoperative anorectal manometry, endorectal ultrasound. The period of postoperative monitoring is from 6 to 12 months, control examinations with a functional study of the anal sphincters were carried out 1 and 2 months after healing. Concomitant hemorrhoids were noted in 65 (31.5%) patients, of which 20 (9.7%) patients were simultaneously hemorrhoidectomized. In 11 (5.3%) patients, simultaneous operations were performed in the presence of paraproctitis, rectal fistula. Results. In 77.8% of patients with acute fissures, the use of conservative therapy, which included myotropic antispasmodics and local application of glycerol trinitrate made it possible to achieve healing of fissures without surgery. Operated 185 (89.8%) patients. With an increase in the basal anal pressure at the level of the internal sphincter, an increase in the average pressure in the anal canal, a decrease in the amplitude and duration of the rectoanal reflex, the indications for dosed sphincterotomy were determined in 167 patients. At the same time, in 117 persons, the excision of fissures was supplemented with a lateral “closed” sphincterotomy, in 50 cases the posterior «open» dosed sphincterotomy was performed. In 18 (9.7% of the operated ones) patients in the absence of sphincter hypertonus, the fissures were excised without sphincterotomy. The best functional results were obtained after performing the lateral «closed» subcutaneous sphincterotomy. It was noticed that in the absence of characteristic complaints and clinical manifestations of incontinence, in 14 patients there was a decrease in the average pressure in the anal canal at rest and with volitional contraction. At the same time, 6 patients out of 14 belonged to the older age groups, and in 9 women there was a rectocele, pelvic floor prolapse. Postoperative incontinence was not observed. Recovery with complete epithelialization of the anoderm defect and the absence of complaints was achieved in 191 (92.7%) patients, satisfactory results (healing of fissures in the presence of pain or proctitis) — in 8 (3.9%) and in 7 (3.4%) patients relapse of the disease was noted with the ineffectiveness of therapy. Conclusions. The ineffectiveness of complex conservative treatment for more than two weeks, with a history of more than 3 months, is an indication for surgical treatment. Preoperative functional and clinical and physiological examination of patients allows the formation of surgical tactics. A differentiated approach to the choice of treatment method, as well as individual determination of indications for surgery and sphincterotomy can improve long-term results. The technique of simultaneous operations with the combination of anal fissure and other proctological diseases needs to be improved.