OBJECTIVE To determine whether or not diaphragm electromyography recorded from chest wall surface electrodes (EMGsur) can be used to distinguish central from obstructive sleep apnea. METHODS Ten patients (age (44 ± 10) years, body mass index (25.9 ± 1.8) kg/m²) with suspected obstructive sleep apnea referred from Guangzhou Institute of Respiratory Disease were studied between January and September 2009. EMGsur and diaphragm electromyography from esophageal electrode (EMGeso) were recorded during conventional overnight full polysomnography. And chest-abdominal movement was measured with chest and abdominal bands. RESULTS High-quality EMGsur and EMGeso were recorded in all subjects except for one who could not tolerate a multipair esophageal electrode. Excellent correlation was found between EMGsur and EMGeso during sleep including apnea events (r = 0.81 ± 0.06, P < 0.05). The central sleep apnea events diagnosed by EMGeso were exactly the same as those diagnosed by EMGsur. However, the central sleep apnea events diagnosed by EMGsur were less than those diagnosed by conventional thoracic-abdominal bands (7 ± 11 vs 28 ± 31, P < 0.05). CONCLUSIONS EMGsur may be used to distinguish central from obstructive sleep apnea events.