Sleep-disordered breathing (SDB) is a condition of repetitive episodes of decreased or arrested respiratory airflow during sleep. Many workers over the world remain undiagnosed and untreated for SDB, and leaving themselves at the high risk for accidents and cardiovascular disease. Since, the Japanese Ministry of Land, Infrastructure and Transport distributed the sleep apnea syndrome manual together with sending an official notice to relevant bodies in all over Japan in March, 2003, employees and employers are expected to co-operate to prevent SDB-related accidents at work. We have conducted several surveys using the pulse-oximetry to detect SDB in working populations and found the high prevalence of SDB among workers in Japan, as many as in the US and EU countries. The proper use of the result from the screening for SDB seems to be beneficial both to workers and employers by maintaining occupational safety and by preventing future development of cardiovascular disease.