The promotion and support of urban agriculture (UA) has the potential to contribute to efforts to address pressing challenges of poverty, under nutrition and sustainability among vulnerable populations in the growing cities of sub-Saharan Africa (SSA). This may be especially relevant for HIV/AIDS-affected individuals in SSA whose agricultural livelihoods are severely disrupted by the devastating effects of the disease on physical productivity and nutritional well-being. This paper outlines the process involved in the conception, design and implementation of a project to strengthen technical, environmental, financial and social capacity for UA among HIV-affected households in Nakuru, Kenya. Key lessons learned are also discussed. The first has been the value of multi-stakeholder partnerships, representing a broad range of relevant experience, knowledge and perspectives in order to address the complex set of issues facing agriculture for social purposes in urban settings. A second is the key role of self-help group organizations, and the securing of institutional commitments to support farming by vulnerable persons affected by HIV-AIDS is also apparent. Finally, the usefulness of evaluative tools using mixed methods to monitor progress towards goals and identify supports and barriers to success are highlighted.