OBJECTIVE: To present findings from implementation and scale-up of human immunodeficiency virus (HIV) self-testing programmes for female sex workers in Malawi and Zimbabwe, 2013-2018. METHODS: In Zimbabwe, we carried out formative research to assess the acceptability and accuracy of HIV self-testing. During implementation we evaluated sex workers' preferences for, and feasibility of, distribution of test kits before the programme was scaled-up. In Malawi, we conducted a rapid ethnographic assessment to explore the context and needs of female sex workers and resources available, leading to a workshop to define the distribution approach for test kits. Once distribution was implemented, we conducted a process evaluation and established a system for monitoring social harm. FINDINGS: In Zimbabwe, female sex workers were able to accurately self-test. The preference study helped to refine systems for national scale-up through existing services for female sex workers. The qualitative data helped to identify additional distribution strategies and mediate potential social harm to women. In Malawi, peer distribution of test kits was the preferred strategy. We identified some incidents of social harm among peer distributors and female sex workers, as well as supply-side barriers to implementation which hindered uptake of testing. CONCLUSION: Involving female sex workers in planning and ongoing implementation of HIV self-testing is essential, along with strategies to mitigate potential harm. Optimal strategies for distribution and post-test support are context-specific and need to consider existing support for female sex workers and levels of trust and cohesion within their communities.