Objective: The purpose of this investigation was to determine the clinical efficiency of the intramuscular injection of botulinum toxin type A as an alternative approach for patients diagnosed with masseteric hypertrophy at Hospital Simón Bolívar and Hospital Universitario Clínica San Rafael in Bogota, Colombia. Patients and methods: A retrospective case-series investigation was performed. It included healthy patients diagnosed with masseteric hypertrophy and treated by means of an intramuscular injection of botulinum toxin type A, between January 2011 and October 2013. Study variables included patient’s medical and dental history, demographics, medication dose and complications. Three outcome variables were measured: Clinical absence or reduction of masseteric hypertrophy, pain and bruxism. Descriptive statistics were computed for each study variable. Results: A total of 20 patients were studied (5 men and 15 women) and the sample’s mean age was 29.5 years. After a 6-month follow-up appointment, 15 % of patients presented masseteric hypertrophy, 15 % moderate pain and 85 % mild pain. Only 10 % presented bruxism.