This article reports findings from the first phase of a longitudinal, qualitative study based on a cohort of 50 gamblers. The overall study is designed to explore the development of 'gambling careers'. Within it, this first phase of analysis examines the ways that individuals begin gambling, focusing on the role of social relationships and environmental context in this process. Drawing on theories of social learning and cultural capital, we argue that gambling is a fundamentally social behaviour that is embedded in specific environmental and cultural settings. Our findings reveal the importance of social networks, such as family, friends and colleagues, as well as geographical-cultural environment, social class, age and gender, in the initiation of gambling behaviour. They also suggest that those who begin gambling at an early age within family networks are more likely to develop problems than those who begin later, amongst friends and colleagues. However, we caution against simplistic interpretations, as a variety of inter-dependent social factors interact in complex ways here.