This literature review provides an overview of the main lines of discussion and enquiry around social capital and adult learning and literacy. It was written as a background paper for "The Centre for Literacy's 2010 Summer Institute" on workplace literacy and essential skills (LES). The Institute focus was "what 'counts' and why", an effort to better understand the outcomes of workplace LES initiatives and how to measure them. Initial research turned up considerable debate about human and social capital outcomes of learning and how these might relate to workplace education settings. Most of the literature on social capital in connection to adult learning and literacy has appeared in the last decade. This review surveys that literature summarizing findings and analyses from major studies. It describes and defines the concept and its growing importance, and focuses on the social capital outcomes of programs and their measurement. The review is divided into seven sections, plus concluding remarks, three appendices, and a bibliography. The appendices present: (1) The Key Elements of Social Capital and Related Indicators in the ABS Framework; (2) Dymock and Billet's Six Instruments; and (3) Some Recent Tools for Measuring Self-Confidence.