Aim. The objective of the present study was to assess the influence of posterisan on the healing of the postoperative wounds of the anal canal and perineum. Material and methods. The study included 102 patients of either sex at the age varying from 18 to 60 years who presented with the chronic anal fissure. Based on the results of the preoperative examination including prophilometry, the patients were hospitalized and randomized into two groups. Group 1 (control) was comprised of 48 patients, while 54 patients included into group 2 were treated postoperatively with the posterisan ointment. All the patients in both groups underwent the surgical treatment in the form of dissection of the anal fissure with or without pheumodivulsion of the anal sphincter. The patients were repeatedly examined on days 2, 15, and 28 of the postoperative period. They received the standard post-surgical treatment and underwent the evaluation of their ability to care for themselves based on the Barthel scale and the quality of life with the use of the QoL SF-36 scale prior to and on day 28 after surgery. Results. The study has demonstrated the positive influence of posterisan on the following characteristics of the patients: the frequency and duration of hyperthermia (56% and 8% respectively) during two days in the main group in comparison with 83% and 48% in the control group during the same period. The local inflammation was totally absent within 15 days after surgery in all the patients of the main group in contrast to the control group in which it occurred in 59% of the patients. Complete epithelization was documented on postoperative day 28 in 63% of the patients in the main group in comparison with 4% among the controls. Dynamics of the area of the postoperative wounds was manifest as follows: in the patients of the main group the wound area was 34% and 41% smaller than in the control patients within 15 and 28 days after surgery respectively. The frequency of late postoperative complications was estimated at 10.4%, in the control group and they were totally absent in the patients of the main group. Not a single case of adverse reactions attributable to the application of posterisan was registered. Conclusion. The application of the posterisan ointment for the postoperative treatment of the chronic anal fissure provides an efficient and safe method for the decrease of local inflammation and the frequency of late complications; as a result, posterisan therapy allows to reduce the duration of the hospital stay for the patients after the surgical treatment of the chronic anal fissure. This preparation can be recommended for the more extensive application in the routine clinical practice.