Subject of this paper is the project of building a self-service automatic car wash with associated infrastructure in the municipality of Trešnjevka - South, Zagreb. The idea was developed by a young entrepreneur in response to the negative experiences of users regarding the quality of service and maintenance of facilities in car washes in this part of Zagreb. The second drive was growing demand as a result of the increase in the number of cars and the degree of care of owners about their vehicles. The aim of this study is set for the development of a project for the construction of a self-service automatic car wash, which will be realized with the application of theoretical and practical knowledge acquired during the studies. The project has clearly defined goals that, in addition to economic profitability, deal very seriously with the environmental impact that this car wash will have and reduce them to a minimum. For the needs of project preparation and execution, the necessary research was performed, certain procedures and calculations were performed in order to assess the cost-effectiveness of the project. The results of research and analysis indicate a well-recognized and addressed problem of lack of defined service of the desired quality, as well as insufficient care for the environment in existing car washes. Furthermore, economic analyzes speak in favor of initiating the investment and state an acceptable investment return period of 6 years, with the possibility of continuing exploitation without additional investment in the reconstruction of the built infrastructure. A well-conceived and elaborate appearance on the market with the use of "branding" based on quality of service, reasonable prices and care for the environment, will ensure the attraction and retention of new customers. Finally, based on the values of all indicators of project cost-effectiveness assessment and plans developed in this study, the project team recommends the implementation of the project. The company's vision is to become a market leader relying on its own potential and an innovative and dynamic approach to the market. Therefore, the project is suitable for multiple realizations due to high market demand, which will enable the development of the project organization and the expansion of the established company.