SETTING: The Northern Cape province, Republic of South Africa. OBJECTIVES: To explore factors that motivate lay volunteers to join tuberculosis (TB) control programmes in high burden but resource-limited settings. DESIGN: A qualitative study consisting of three focus group discussions and a documentary review of the records of 347 lay volunteers involved in the tuberculosis programme in the Northern Cape province of South Africa. Additional data were also collected in a cross-sectional study that involved questionnaire interviews with 135 lay volunteers. SUBJECTS: Lay volunteers in the TB programme. One focus group discussion was also carried out with youth not involved in the TB programme. RESULTS: Volunteers do not receive any monetary incentives in the TB programme in the Northern Cape province, but due to the high level of unemployment in this setting, hope for eventual remuneration was found to be the strongest factor motivating youth to join the programme. The study found attrition rates among volunteers to be high (22% had dropped out of the programme within one year of joining); 75% of the dropouts gave loss of interest and a desire for paid work as the reasons for leaving the TB programme. Other motivating factors identified included altruism, a need to find something to do with one's spare time, gaining work experience, and the novelty of the community-based TB programme. CONCLUSION: In the absence of monetary incentives, attrition rates of lay volunteers may be high and this can threaten the effectiveness of community-based TB programmes. In resource-limited settings, it is important to identify and implement appropriate alternative incentives that could motivate lay persons in order to sustain community participation in high TB burden areas.