SUMMARY. Background The occurrence of obstructive sleep apnoea in children with achondroplasia has already been described. Objectives To investigate the association between achondroplasia and obstructive sleep apnoea syndrome (OSAS) in adult patients. Subjects and methods Three women aged 43-59 years with achondroplasia were studied. They all complained of snoring, daytime somnolence and chronic fatigue. Their past history included tonsillectomy and adenoidectomy. Polysomnography, spirometry, blood gases and blood biochemistry analysis were performed. Results All three women had OSAS, with RDI 42.8/h, 23.3/h, 40.1/h respectively. Spirometry and arterial blood gases were within normal limits, but blood biochemistry showed hyperlipidaemia in all the women. Cephalometry showed middle face hypoplasia. Neck CT-MRI demonstrated constriction of the foramen magnum amd stenosis of the oropharynx and hypopharynx. Conclusions OSAS should always be suspected in adult patients with achondroplasia, as well as in patients with skeletal deformities of the face and upper airway soft tissue abnormalities. Pneumon 2008; 21(4):–