In major cities in Turkey, indoor parking facilities can acquire car wash service operation licence. It is very important to alert the employees on such facilities about this health issue. This can be considered as an occupational disease. In this study, the pulse COHb levels of the car washers working at indoor car wash facilities were found to be at levels that can necessitate clinical intervention. It is evident that these workers are subjected to chronic repetitive exposure to CO. Therefore, caution should be exercised, especially about chronic sequelae. It was found out that none of the workers included in this study had any idea about the possibility of CO poisoning due to their working conditions. Based on the results of this study, it can be concluded that working at indoor carwash facilities carry occupational health hazards. Therefore, workers in such facilities should be aware of using personal protective equipments such as masks as a protective measure