This handbook prepared by the International Federation Reference Centre for Psychosocial Support (the PS Centre) reflects the increasingly active role that the Red Cross Red Crescent Movement plays in psychosocial responses. The development of the handbook is a result of collecting lessons learned on the many varied psychosocial interventions that have been implemented in different countries recently, with a particular focus on the psychosocial response to the Indian Ocean tsunami of December 2004. This event led to one of the largest emergency responses in history, with the involvement of a multitude of organisations and individuals in many varied psycho-social interventions. These interventions helped thousandsof communities, families and individuals and contributed to increasing global awareness on psychosocial needs and responses following critical events and during crises.