- To assess the awareness level of primary care physicians of obstructive sleep apnea syndrome during patient-physician encounters. A prospective study using a standardized patient approach, conducted between December 2001 and March 2002. Ten sleep experts reviewed and approved the checklist questionnaire. Primary care clinics of Clalit Health Care Services, in the central region of Israel. Thirty physicians (100% compliance) randomly selected (matched by age, sex, board certification) from the 261 primary care givers in the region. A standardized patient incorporated into the physicians' daily practices. From the original checklist questionnaire, we identified 2 related question areas that at least 90% of sleep experts would pursue in light of the presenting scenario, "Do the patients snore, choke, or stop breathing in sleep?" and "Does the patient have sleepiness, unrefreshed sleep/fall asleep at undesirable times?" During the unstructured interview, only 10% of the physicians asked 3 or more questions. More than 85% of primary care physicians identified the need for polysomnography evaluation (27 physicians) or continuous positive airway pressure (26 physicians) treatment for obstructive sleep apnea syndrome. However, only 16% and 50% discussed possible complications of obstructive sleep apnea syndrome such as motor vehicle and work accidents and cardiovascular events, respectively. Primary care physicians cannot identify a common disorder associated with cardiovascular and neurobehavioral disease and could not identify the sleepiness as a source of dangerous driving. While understanding the algorithms for the diagnosis of sleep apnea, physicians cannot identify the patients for whom the diagnostics are needed. Education programs need to be developed to increase the level of suspicion of obstructive sleep apnea syndrome among practicing primary care physicians. Activities can be monitored and evaluated over time in the daily practice by standardized patients. Increased awareness level of obstructive sleep apnea syndrome among primary care physicians, through publications and educational programs, monitored by standardized patients.