This literature review, which was commissioned by the UK's Small Business Service is concerned with business networks, and their importance for the small business community. Business networks are sometimes defined as comprising only inter-firm relationships (e.g. those that exist between component supplier and a manufacturer). However, it soon becomes apparent that a broader perspective is required, if research findings are to contribute meaningful insights for policy and practice. We have therefore incorporated research evidence on personal networks, notably those associated with entrepreneurship, and on links between firms and supporting institutions, such as trade associations, government agencies and universities