BACKGROUND: Socioeconomic support reduced non-retention in a community-based antiretroviral therapy (ART) program in Uganda. However, the resource implications of expanding socioeconomic support are large, and cost-effectiveness analysis can inform budget priorities. We compared the incremental benefits and costs of providing education, food or both forms of support (dual support) with existing ART services from a health care provider's perspective. METHODS: Costs and outcome data were collected from a cohort of 2371 adult HIV patients receiving education, food or dual support from Reach Out Mbuya (ROM) between 2004-2010. The primary outcome was averted loss to follow-up (LTFU).The number of follow-up days was calculated for each patient along with accrued service and fixed program costs for the alternative forms of socioeconomic support in USD via standard costing methods. The socioeconomic support types were compared incrementally over the study period. FINDINGS: After 7 years, 762 (33%) of the patients were LTFU with 42% of them receiving food. In the presence of providing ART, education support was less costly and more effective than the alternatives. The average unit cost for education, food and dual support were $237, $538 and $776 respectively. The average total annual costs were $88,643 for education, $538,005 for food and $103,045 for dual support. CONCLUSION: Compared to food or dual support, investing in education of the children of ART patients is less costly and more effective in improving patient retention. ROM should embrace this paradigm shift and channel its resources more efficiently and effectively by focusing on education support.