Written and edited by experts in the field, this collection from Cold Spring Harbor Perspectives in Biology describes recent progress in our understanding of early heart development and the various cell lineages involved, as well as mechanisms and models of congenital heart disease. The contributors discuss early cardiac morphogenesis and anatomy, the origins of contractile activity, the control of cardiac growth and size, and the signaling pathways and transcription programs that underpin these processes. Specific chapters are devoted to various muscle and non-muscle cell lineages involved in heart development, including those of the neural crest, endo- and epicardium, fibroblasts, coronary vessels, and cardiac conduction and lymphatic systems.