Background: The aim of this study was to assess the prevalence of Obstructive sleep apnoea syndrome (OSAS) in long-distance drivers located in the Zonguldak area and to show the correlation between OSAS and traffic accidents.,Methods: In this study, 241 long-distance drivers who were residents of Zonguldak province were interviewed face-to-face and a questionnaire regarding OSAS symptoms, occupational histories, and numbers of accidents was administered. Body mass measurements were also taken from participants. Patients who exhibited evidence of OSAS underwent polysomnography (PSG).,Results: Snoring was detected in 56% out of all participants, daytime sleepiness was observed in 26.6% and apnoea in 11.6%. All-night PSG was applied to 42 participants who had a high probability of clinical OSAS. Among these, eight had an apnoea-hypopnoea index (AHI) < 5. The prevalence of OSAS was 14.1%. There was a significant relationship between the ratio of traffic accidents per professional years and AHI (r = 0.571; p < 0.005).,Conclusions: OSAS prevalence was higher among long-distance drivers in the Zonguldak region. Disease severity was directly proportional to traffic-accident risk, and thus represents a serious social problem.