Proteus syndrome is a rare condition that involves atypical growth of the bones, skin and head and a variety of other symptoms. Only a few authors have reported on the craniofacial manifestations so far. The authors present a case of a 7-year-old girl with Proteus syndrome in which the facial skeleton showed unilateral overgrowth. The analysis of the radiological evaluation revealed a bialveolar prognathism, a skeletal class III, a dolicocephalic growth pattern and a left convex face scoliosis. On the left side, the lesser wing of the sphenoid was elevated and the ethmoidal cell complex was hypertrophic. The left ramus and body of the mandible were enlarged. The asymmetric dental development with a precocious dental age on the affected side was the most striking feature on the panoramic view. Early diagnosis and therapy depend on clinical evaluation and imaging. Therefore, further evaluations on the craniofacial features of patients with Proteus syndrome are necessary in order to establish a list of characteristic symptoms.