Mandibular fracture in infants is less common. We have encountered a case of 1 year-old patient with fractures of median mandible and right condylar head region. Circumferential fixation with plate after reduction of fracture was performed against median mandibular fracture under general anesthesia, but no treatment was done on right condylar fracture. Internal maxillary fixation was not planned. Circumferential fixation continued for 3 weeks. After this therapy, no abnormality of mandibular function has been observed in this 1 year and 4 months. Careful observation should be continued for long duration in our department.