Small and medium enterprises are a key factor in the economies of the Central and East European transition states. The importance of the SME sector in these economies is correlated with such reasons as demopolization of economy, social stability through the development of the middle class, creation of a significant number of new jobs, etc. The far-reaching economic reforms that began in Poland in 1989, together with changes in the social structure and political system have resulted in rapid development of small and medium size enterprises. SME's development policy faced new challenges after Poland's integration with European Union The first part of the article presents the role of SMEs in the sustained economic development and the actual development of SMEs growth. Next we describe the main policy approaches followed by the Polish government and we identify future opportunities and threats for SME. The main aim of the second part of the paper is to indicate the fact that leasing exerting a considerable influence on the development of SME sector in Polish economy. The analysis conducted in the paper is based on specialist literature, information from the leasing branch and opinions of leasing market experts. The article describes the structure of leasing, potential directions of development and main barriers for the development of the most important types of leasing transactions.