The influence of position during sleep on central apnoeas during Cheyne-Stokes respiration has not previously been studied systematically. The current authors aimed to study the effect of body position and sleep stages on central sleep apnoeas during Cheyne-Stokes respiration. A total of 20 consecutive patients with cardiovascular diseases and central sleep apnoea during Cheyne-Stokes respiration were investigated using nocturnal polysomnography, including a body position sensor mounted on the patient's sternum. The mean central apnoea-hypopnoea index was significantly higher in the supine position than in nonsupine positions (41±13 versus 26±12). The central apnoea-hypopnoea index was highest in sleep stages 1 and 2, and lowest in slow-wave sleep and rapid eye movement sleep. In every sleep stage, central apnoeas and hypopnoeas were more prevalent in the supine position compared with nonsupine positions. In conclusion, sleep in the supine body position increases the frequency of apnoeas and hypopnoeas in patients with Cheyne-Stokes respiration. Copyright©ERS Journals Ltd 2005.