The aim of this research is to explore managerial factors affecting the success of new product development projects in small and medium sized enterprises. To find out these factors, deep interviews are conducted with successful managers in the field of new product development. Afterwards, a survey is conducted to production/sales/marketing/R&D managers and chief executive officers of small and medium sized enterprises to elicit their points of view. This study examines five factors assumed to be critical to influence on the top managers to achieve their success in the new product development. These factors include commitment, entrepreneurial orientation, social capital, international orientation and tendency to future studies of top managers.