Analysis of networks is increasingly seen as important for understanding the patterns, processes and consequences of social relationships in healthcare. Networks can be formal, mandated structures (e.g., a clinical network), can emerge from sharing a common passion, or from routine exchanges such as referrals. Braithwaite and colleagues call for the fostering of naturally emerging networks suggesting these underpin the delivery of healthcare and play an important role in driving quality and safety. Social network analysis (SNA) emphasizes patterns of relationships and interactions between network members (actors) rather than individual attributes/behaviours or abstract social structures. SNA conceptualizes networks as composed of nodes (the actors in the group) and ties (the relationship between the actors). Ties form the structure of the network and the nodes occupy positions within that structure. This proves a basis to investigate a wide range of issues, including communication pathways between actors (including gaps, bottlenecks or opportunities to increase connectivity), the presence of "tribes" or silos, key players, networks of social support, and patterns of social influences on behaviours. This also allows researchers to investigate relationships between network structures (e.g., communication flows) and important outcomes (e.g., rapid dissemination of ideas).In this chapter, we will introduce readers to key debates, concepts, methods and applications of SNA, drawing on the authors' own studies and the growing body of healthcare literature adopting this approach. This demonstrates the contribution of SNA to understanding different types of networks, including at the individual, group and organizational level.