British planners are becoming increasingly interested in the social implications of planning and the potential contribution of social research to their work. Though the opportunity presented by the new towns was largely ignored, there has been some research in new communities in Britain, particularly in recent years. A review of three selected issues on which social research has been undertaken shows how such research can illuminate the social consequences of planning. The description of a recent experience of collaboration between planners and sociologists—in preparing for a major town expansion scheme—gives a practical illustration of what can be done and suggests some of the implications for the future.