Group work in the Singapore Prison Service (SPS) started in 2001 and has remained as the main channel for rehabilitation to take place. This book explores the transformative power of group therapy within a correctional setting, offering a comprehensive guide for therapists, psychologists, counsellors and prison staff who facilitate therapeutic groups for incarcerated individuals. Grounded in evidence-informed practices, this work delves into SPS's progressive and professional approaches in rehabilitation through the lens of specialists and correctional officers who lead intervention groups for prisoners and drug abusers accumulated over the last two decades.The book provides insights into the unique ethical considerations of leading groups in a prison setting, and the role correctional officers can also play in leading groups. With real-life case studies, facilitator tips and guidance on managing group dynamics in a high-security environment, the book provides practitioners with the knowledge and understanding about working with individuals to improve decision-making skills, and fostering positive behavioural change.