The UNDP/World Bank/UNAIDS HIV Mainstreaming Programme was initiated in 2005 and launched its final round in 2009, expanding its support to four countries in Southern Africa (Botswana, Lesotho, Namibia and Swaziland). The addition of the Round 4 countries brings the total number of participating countries to 28 across all UNDP regions. An independent evaluation of the initiative was conducted in three of the participating countries (Burkina Faso, Rwanda and Tanzania. This assessment will contribute to the wider dissemination of best practices on mainstreaming in various settings, as well as provide lessons learned and recommendations on addressing key challenges.