There is considerable interest in teacher development at present. This is especially so at underperforming schools, where teacher development is seen as an essential ingredient in transforming these schools into performing schools. Since many teachers at these schools might be reluctant to participate in development activities, it is important to identify the factors that might motivate them to do so. This article first surveys the literature on aspects of motivation, professional development and adult learning principles in relation to contextual factors that affect underperforming schools and various motivation theories. The article then reports on a qualitative study that was used to explore the factors that motivate teachers to participate in development activities. These are related to theories of motivation as well as principles of adult learning. The underlying assumption is that a greater understanding of these factors could help development programme designers devise ways of encouraging teachers at underperforming schools to participate in professional development activities.