In this study, the definition of work accident was made and then the concept of work accident in construction works was explained. The last five years of work accident statistics published by the Social Security Institution were examined. According to these statistics, the accident rates of the construction sector in all sectors were found by making use of the annual number of occupational accidents and fatal occupational accidents. Approximately one third of the fatal occupational accidents in our country occur in the construction sector. Occupational accident statistics of the construction sector are grouped under three headings according to the Nace economic classification codes. According to the work accident statistics examinations in these three categories, the most work accidents and the most deaths as a result of work accidents occurred in building construction works. In line with this information, occupational accidents and occupational safety costs in building construction works were examined. The data were obtained from surveys and interviews with construction companies, occupational safety companies, and consulting companies. Occupational health and safety costs; The costs of the OHS personnel employed, the cost of environmental safety measures taken to prevent occupational accidents at the construction site, the cost of health expenditures of the employees and the cost of personal protective equipment were examined under four main headings and the total cost per m2 was calculated. Moreover, the cost to the contractor is calculated and compared with the occupational safety costs in the construction sites where work accidents “resulting in death and injury” occur. Although the place of occupational health and safety costs in the total construction costs is quite low, the importance of occupational health and safety in the construction sector is emphasized by evaluating the consequences and costs of avoiding these measures through examples.