The Training of Trainers Manual is a training curriculum developed under the Youth Peer initiative through a partnership with UNFPA and Family Health International (FHI)/Youth Net, in 2005. It provides a comprehensive training programme that can be used by "master" level peer educators and trainers. The manual uses participatory techniques based on a variety of theoretical frameworks to ensure that future trainers of peer educators are skilled and confident in their abilities to train peer educators and serve as informed resources for their peers. It also explains how the work of peer educators fits within a systematic approach to behaviour change on individual and societal levels. Special attention is given to gender and cultural sensitivity and to youth participation in health education. This manual can be used by anyone seeking to provide higher level training to experienced peer educators on issues related to the design, implementation, and evaluation of peer education programmes. The document is composed of four main sections: I) Section 1. From Theory to Practice in Peer Education reviews the definition of peer education and its rationale and value in the context of different behaviour change theories and models. II) Section 2. Guidelines for Training of Trainers: A Curriculum provides the outline of a suggested six-day training of trainers (TOT) workshop. For each of the training topics, the curriculum provides appropriate training exercises and notes. The exercises are described in detail so that they can be reproduced easily in future trainings. III) Section 3. A Sample Peer Education Session on HIV/AIDS presents an example of a peer education activity for use in the field. It describes a three- to four-hour HIV/AIDS education session that can be presented to a group of adolescents. IV) Section 4. Participant Handouts includes 20 handouts that are used in the six-day training. Several annexes are included as well.