Since development agencies often implement interventions through collective-action groups such as farmer cooperatives and self-help groups, there is a need to understand how participation is affected by group-level and leader attributes. This study collected gender-disaggregated, quantitative and qualitative data on sixty-eight self-help groups in Zambia to understand the participation of men and women farmers in different crop-production activities. Results show that participation rates of men and women are the same across all maize production activities except harvesting.