Habitual heavy snoring may be considered a preliminary stage of sleep apnea syndrome. This investigation deals with the craniofacial morphology of 51 heavily snoring patients, with and without obstructive sleep apnea, and with 28 healthy control patients. The apnea group showed a reduced posterior airway and a posterior rotation of the mandible. Reduction of the anterior-posterior diameter of the cranial base, maxilla and mandible and vertical reduction of the posterior facial height appeared to be common facial characteristics in both snoring and apnea patients. These findings indicate an anatomical disposition for snoring and apnea.