Introduction: Lateral internal sphincterotomy is the technique of choice for the management of chronic anal fissure. Botulinum toxin has lower complete cure rates, but with significantly lower risk of incontinence. Aim: To evaluate the healing rate, postoperative fecal incontinence and quality of life in patients with chronic anal fissure managed with botulinum toxin. Materials and Methods: Retros-pective, prospective, observational and cross-sectional cohort study with consecutive patients. Patients with chronic anal fissure managed with injection of botulinum toxin at the Clinical Hospital of the University of Chile between March 2017 and September 2022 were included. Results: 19 patients, to whom botulinum toxin was administered. Complete healing of the fissure was achieved in all patients, with transient and exclusive fecal incontinence only to gas, which subsided during follow-up. There is a significant improvement in postoperative quality of life. Discussion: Botulinum toxin is a good alternative for the management of chronic anal fissure, with lower healing rates than standard treatment, but a lower proportion of fecal incontinence, generating a relevant benefit. There are no other publications that evaluate quality of life after treatment with botulinum toxin. Conclusion: The administration of botulinum toxin in patients with chronic anal fissure showed promising results in terms of healing, fecal incontinence and postoperative quality of life. In accordance with the recommendations of the American and British guidelines, it should be considered as a therapeutic alternative, especially in patients at high risk of permanent fecal incontinence.