Introduction: Chronic mandibular osteomyelitis is considered to be an odontogenic infection manifesting as facial tumefaction, limited mouth opening and pain. It is not often enough treated with ciprofloxacin fixation gammagraphies with the consequent achievement of effective results. Objective: Describe a clinical case of chronic mandibular osteomyelitis treated with antibiotic and surgical therapy. Case presentation: A female 63-year-old patient attends the dental service at María Auxiliadora Hospital in Lima, Peru, with a history of three-months' swelling of the lower left edge of her mandible upon performance of a dental extraction. Tomographic examination, gammagraphy, biopsy and antibiograms confirmed the presence of osteomyelitis and bacterial susceptibility. Decortication, debridement, exodontia and administration of metronidazole plus vancomycin for two months led to remission of the patient's status. Conclusions: Two-year clinical follow-up and evaluation gammagraphies made it possible to verify the presence of bone regeneration and the absence of reactivation foci. Chronic osteomyelitis may be caused by remains of dental exodontias. Its diagnosis and clinical follow-up require a large number of long-term tests and controls.