This paper explores the contribution that action learning can make to the formation of social capital via experiences of action learning projects in NHS Pathology Services in the UK. The paper describes the development of action learning practice in recent years, reviews the notion of social capital and considers how action learning might contribute to its formation. A case study of action learning in the development of a locally unified pathology service is used to illustrate the processes by which actions and learnings may be transferred and extended from sets to contribute to organisational learning in wider systems and networks. (Contains 1 notes.)