The objective of the study was to establish the relationship between functional status of bronchopulmonary system and obstructive sleep apnea in clean-up workers of Chornobyl NPP accident in a remote post-accident period. Materials and methods. We included 58 COPD male patients clean-up workers of Chornobyl NPP accident: 21 with obstructive sleep apnea syndrome (OSA), 37 – without. A complex of functional tests and OSA screening was provided. Results. In clean-up workers of Chornobyl NPP accident with COPD and obstructive sleep apnea in a remote postaccident period apnea–hypopnea index (AHI) negatively correlated with FVC, % of predicted (r = -0.36, p < 0.05), the intrathoracic gas volume (ITGV), % of predicted (r = -0.40, p < 0.05); AHI positively correlated with diffusion lung capacity (DLCO), % of predicted values (r = 0.57, p < 0.05), with the intrathoracic gas volume (ITGV), % of predicted (r = 0.53, p < 0.05), body mass index (r = 0.49, p < 0.05) and age (r = 0.62, p < 0.05). Conclusions. Obstructive sleep apnea was diagnosed in 36.3 % of patients with COPD clean up workers of Chornobyl NPP accident. Screening for OSA in patients with COPD, clean-up workers of Chornobyl NPP accident is a very important clinical task for prognosis and treatment Key words: clean-up workers of Chornobyl NPP accident, pulmonary function tests, obstructive sleep apnea.