Volatile organic compounds (VOCs) are some of the most important pollutants that have adverse effects on human health. In this study, simultaneous indoor and outdoor air samples were collected from four types of microenvironments (restaurants, photocopy centers, dry cleaners, and auto paint shops) in Kocaeli, Turkey in both winter and summer. Twenty-four VOCs were detected using gas chromatography and a flame ionization detector. The aim of the study was to determine the VOC concentrations in various workplaces and investigate associated health risks. Results show that the highest mean total VOC concentrations are in auto paint shops (14,066 mu g/m(3) in winter, 3441 mu g/m(3) in summer) followed by dry cleaners, restaurants, and photocopy centers. Total cancer risk was approximately 310 times greater than the acceptable limit in auto paint shops, 44 times greater in restaurants, 42 times greater in dry cleaners, and 17 times greater in photocopy centers. Total hazard quotients were also greater than the acceptable limit in all microenvironments.