This manual is intended for social science and medical researchers who require information quickly on a particular topic of study, to learn about social and cultural issues relating to disease control prevention and treatment. Listed applications include exploratory studies, testing ideas about new programmes, solving specific programme problems, evaluating programmes, and solving staff/management problems. Focus group discussions (FGD) can be "an effective way to get this information and to reveal the range of opinion in a community". FGDs "are formally constituted, structured groups of people brought together to address a specific issue within a fixed time frame and in accordance with clearly spelled out rules of procedure". This manual explains how to organise and conduct these groups. Part I describes the purposes, structure and conduct of FGDs, and some techniques for keeping discussion going. Part I is aimed at researchers or others responsible for a project and who may be training others to use FGDs. Part II is a series of training sessions for others involved in the project. Special attention is given to FGDs which use interpreters, and Pt. II section 5 discusses the importance of listening skills, being non-judgmental, and other appropriate behaviour. Examples used relate to tropical disease research.