The 10 th International Days of Statistics and Economics, Prague, September 8-10, 2016 2056 INNOVATIVE ACTIVITIES OF SMALL AND MEDIUM- SIZED ENTERPRISES IN POLAND Anna Wolak-Tuzimek Abstract Specialist literature offers a range of definitions of innovation. It most commonly denotes implementation of new or significantly improved product, manufacturing process, organisation and marketing solutions to economic practice. This paper is aimed at analysing and evaluating innovation activities of enterprises in the Polish economy. It presents results of the author's research into 106 enterprises operating in the Mazovian region concerning the period 2010-2014. Four research hypotheses are postulated, concerning the dependence between size of an enterprise and frequency of its innovation activities, reasons for and limitations to implementing innovations by enterprises, and the most common types of innovations introduced to businesses. The research undertaken suggests small enterprises introduce innovations less frequently than medium-sized businesses do. Entrepreneurs normally state the following are the most common reasons for introducing innovations: expansion of the product range, improvement of product quality, increasing market share and improving competitiveness. Shortage of financial resources for such actions is the most frequently declared reason for not introducing innovations, on the other hand. Small and medium-sized enterprises primarily introduce changes that consist in improvement of existing products, introduction of a new product or of new marketing methods, including changes to product packaging, promotion or pricing. Key words: innovation, enterprises, competitiveness. JEL Code: O31,O32,L25. Introduction The importance of innovation and advanced technologies as factors determining economic processes is growing in the contemporary economy. Innovation standard of an enterprise has