Patterns of wear on the canine teeth were examined in 260 adult male babirusa skulls. Video recordings of 161 adult male babirusas at salt licks in North Sulawesi were viewed for behaviour related to erosion of the canine teeth. Corresponding observations were made of the behaviour of male babirusa in Antwerp and Surabaya Zoos. Most loss of maxillary canine dental tissue was from the ventro-lateral or lateral surface of the tooth, towards its distal end. The teeth were smoothly flattened on a plane approximating to the plane formed on the side of the face by the snout, the zygion and the zygomatic process. Mandibular canine dental erosion was on the medial side of that tooth. Rounded smoothness of both teeth was evident rostrally. Ploughing into mud and face rubbing against young trees accounted for the wear of the teeth.