E-commerce has become increasingly popular in the people everyday business and personal lives. For many organizations, competitiveness in e-commerce requires a successful presence on the web. This paper provided an insight about factors affecting business-to-business e-commerce adoption and implementation in small and medium-sized enterprises. The paper is based on a wide literature review, focused on proposing a theoretical model of technological, environmental and organizational factors influencing e-commerce adoption and implementation. The results of the empirical research provided indication to small and medium-sized enterprises interested to adopt business-to-business ecommerce, large companies interested to conduct e-commerce transactions with small and medium sized companies and policy makers.