: Obstructive Sleep Apnea (OSA) is a common disease associated with major cardiovascular diseases. Male subjects are more at higher risk for OSA than female subjects. The Berlin questionnaire is a beneficial screening tool for OSA and has 14 items. The Berlin questionnaire may need some adjustment for Thai or Asian populations. We aimed to find items that should be asked in the Berlin questionnaire to identify high risk for obstructive sleep apnea among Thai male healthcare workers. This study was performed in Thai male healthcare workers over the age of 35 and currently working at the Faculty of Medicine, Khon Kaen University. The Thai version of the Berlin questionnaire was randomly distributed. A study population of 273 subjects was required to provide a confidence value of 95%. An item analysis of the Berlin questionnaire was evaluated as independent factors for being high risk of OSA by using a multivariate logistic regression analysis. Of the 273 distributed questionnaires, 135 subjects returned then (49.5% response rate). Of those, 41 (30.4%) were identified as being at high risk of OSA. Only three items of the Berlin questionnaire, including frequent snoring, high body mass index and hypertension, were independently associated with being at high risk for OSA. In conclusion, the Berlin questionnaire can be shortened to identify high risk for OSA by itself; not polysomnography.