In 132 patients with polysomnographic records suffering from OSAS a cephalometric analysis according to Hasund supplemented by special OSAS-parameters was performed. The statistical analysis showed a correlation between severity of OSAS and width of posterior airway space, length of the soft palate, hyoid position and posterior growth development of the mandible. A principal component analysis showed four groups: 1) prognathic patients, 2) retrognathic patients with narrow PAS, 3) patients with long soft palate and low standing hyoid, and 4) orthognatic obese subjects. Lateral cephalometry is an important contribution to OSAS-diagnostics and should be performed on all OSAS patients in the course of interdisciplinary cooperation.