A case history has been given with the radiographic evidence of the migration, during development of an unerupted mandibular canine from its normal position. In a 30-month period the canine assumed a horizontal position and moved to a site that was apical to the mandibular incisors, still in the confines of the cortical plates. Because erratic movements of unerupted teeth cannot be anticipated, it would seem wise to defer the elective removal of permanent teeth during the mixed dentition stage until the clinician is assured of a normal eruption pattern of the succedaneous teeth.