Abstract: Hemimandibular hyperplasia and hemimandibular elongation are two mandibular growth anomalies affecting one side or one half of the mandible. They both cause mandibular asymmetry and occur due to the abnormal growth pattern. Both pure and mixed forms of both these anomalies have been reported in the literature. The treatment of both these anomalies are different and hence it is essential for the clinician to know how to differentiate between the two anomalies.