In transition economies, the size and ownership structure of enterprises determine their economic behaviour as well as their attitudes towards innovations. Many studies show that one of the key factors accelerating economic performance of the companies is technological transfer from abroad, and that successful implementation of the new know-how is mainly undertaken by medium and large enterprises. The domestic micro and small enterprises located in Polish regions proved to be rather risk-averse and therefore not very innovative. However, their innovative activities accelerate over time, and eventually they catch up with foreign and large enterprises.