Among the plethora of supervision books, Group Supervision is the only one dedicated to working in groups. The strength of group supervision is that it can provide a supportive environment in which practitioners freely share and learn from their own and others’ experience. The Second Edition of this popular text features up-to-date research findings on group supervision in organizations, and further coverage of the challenge of diversity, and ethical decision-making in groups. A new chapter considers the advantages of groups for supervisor development and training, and stresses the urgency for greater accountability and practitioner research.