INTRODUCTION: Sleep length has been associated with obesity and various adverse health outcomes. The possible association of sleep length and respiratory symptoms has not been previously described. The aim of this study was to investigate the association between sleep length and respiratory symptoms and whether such an association existed independent of obesity. METHODS: This is a multicentre, cross-sectional, population-based study performed in 23 centres in 10 different countries. Participants (n=5079, 52.3% males) were adults in the third follow-up of the European Community Respiratory Health Survey III. The mean+/-SD age was 54.2+/-7.1 (age range 39-67 years). Information was collected on general and respiratory health and sleep characteristics. RESULTS: The mean reported nighttime sleep duration was 6.9+/-1.0 hours. Short sleepers (<6 hours per night) were n=387 (7.6%) and long sleepers (>/=9 hours per night) were n=271 (4.3%). Short sleepers were significantly more likely to report all respiratory symptoms (wheezing, waking up with chest tightness, shortness of breath, coughing, phlegm and bronchitis) except asthma after adjusting for age, gender, body mass index (BMI), centre, marital status, exercise and smoking. Excluding BMI from the model covariates did not affect the results. Short sleep was related to 11 out of 16 respiratory and nasal symptoms among subjects with BMI >/=30 and 9 out of 16 symptoms among subjects with BMI <30. Much fewer symptoms were related to long sleep, both for subjects with BMI <30 and >/=30. CONCLUSIONS: Our results show that short sleep duration is associated with many common respiratory symptoms, and this relationship is independent of obesity.