Garre's sclerosing osteomyelitis is a kind of chronic osteomyelitis that is mainly seen in children and adolescents. It was formerly documented only in long bones, particularly tibia. Proliferative osteomyelitis of the jaw was described only in the late 1970s. Since then, this clinical entity is well illustrated in dental literature and is frequently linked with an odontogenic infection, mainly involving permanent teeth. This article describes an atypical manifestation of Garre's osteomyelitis of the mandible in a 7-year-old-girl, which was a result of infection of primary mandibular first molar. Extraction of the primary right first molar and antibiotic treatment resulted in complete healing, clinically and radiologically, after 6 months.