Proboscis lateralis is one of the rare craniofacial congenital anomalies which presents as an obvious deformity of the nose. It tends to occur in male offspring of consanguineous marriages. This is a report of computerized tomography of this rare anomaly. In proboscis lateralis, the nasal cavity on one side is completely normal, while on the affected side it is replaced by a trunk-like process attached to the medial portion of the orbital roof. This anomaly occurs sporadically as an isolated defect or in association with other anomalies. It is usually associated with developmental failure of the paranasal sinuses and the nasolacrimal duct.