Social workers are involved in the recruitment of research participants in a variety of ways. Increased knowledge regarding recruitment issues will allow social workers to expand their role and improve their performance in this area. These individuals should be aware that there is a large body of literature addressing recruitment. This selective review of the literature prior to mid-1992 will focus on the Coronary Primary Prevention Trial, volunteer effects, recruitment sources, the recruitment process, impediments to recruitment, bias in recruitment, the amount of time required to recruit and the impact of recruitment and participation on individuals. This will be followed by a discussion of issues to be addressed in arriving at solutions to recruitment problems.