A lateral roentgencephalometric study to compare the facial morphology of 21 affected and 18 normal members of 8 families with the Stickler syndrome (SS) was undertaken. The affected individuals exhibited two or more of the following four clinical symptoms: (a) flat midface, (b) cleft palate, (c) eye problems, and (d) arthropathy. The diagnostic facial features of the affected individuals as a group were found to be markedly shortened cranial base length, midfacial depth and height, maxillary depth, and mandibular depth, but significantly larger total and lower facial height dimensions. Facial morphology is highly characteristic for the Stickler syndrome. An application of two discriminant function equations (each based on four cephalometric measurements) to our data correctly identified 84.6 to 89.7% of the affected and normal SS family members. These discriminant function equations should be of considerable aid in the clinical diagnosis of the SS patient prior to the onset of symptoms.