The purpose of paper is to identify factors that are of particular importance for the preparation and implementation of projects in local self-government units. The survey was conducted on the sample of local self-governments in the Republic of Serbia by using a structured questionnaire. The research results showed that the key factors for successful preparation and implementation of projects, ranked by importance, are the following: existence of a quality development strategy at the local level based on the appropriate national strategy, adequate competencies of the employees for the preparation and implementation of projects, ensuring a sufficient level of financial resources for pre-financing and co-financing projects, and establishing partnerships with organizations from other sectors. The results of study may be important for understanding ways to improve the current situation, with regard to the preparation and implementation of projects. The research showed that special organizational units for project management should be established in those local self-governments where such units do not exist, encouraging them to continuously work on the preparation of proposal for different projects. Also, before launching official calls for proposals, it is important to work on improving the local development strategy, in order to, depending on the gaps identified in terms of employees' knowledge and competencies, continuously try to enhance them.