The aim of the study was to explore the nature and extent of the association between night eating, other forms of disordered eating and obstructive sleep apnea (OSAS).Eighty-one participants (20 women and 61 men), mean age 53.7 years diagnosed with OSAS were assessed prior to starting treatment. Using a cut-off of > or =25 on the Night Eating Questionnaire (NEQ), 8.6% of the participants screened positive for night eating syndrome (NES). In addition, 7.5% met criteria for a daytime eating disorder. NES was significantly associated with diagnoses of depression, anxiety and eating disorders and was significantly correlated with an impairment of mental quality of life. No associations were found between NES and gender, BMI and the severity of the OSAS. NES does not appear to be closely linked to OSAS; however, in patients with OSAS and NES a significant co-morbidity with psychiatric disorders can be expected which might require additional treatment.