One hundred fifty-seven mandibular fractures in 105 dogs occurred most frequently in male dogs less than 1 year of age. Automobile trauma was the most common cause. Fractures in the premolar region were significantly more frequent than fractures in other regions, and 113 fractures (72%) were open. One hundred forty-two fractures were stabilized, with tape muzzles being the most common method. Postoperative complications, the most common being dental malocclusion, occurred in 53 fractures (34%). Acceptable cosmetic and functional results were achieved in 89 dogs (85%). Fractures in the rostra1 portion of the mandible had shorter average time to clinical union than other mandibular fractures. Average time to clinical union for fractures in the caudal portions of the mandible was longer than that currently reported.