UNITAID’s mission is to contribute to scaling up access to treatment for HIV/AIDS, malaria and tuberculosis, primarily for people in low-income countries, by leveraging price reductions for quality diagnostics and medicines and accelerating the pace at which these are made available.

UNITAID was established to support existing efforts to achieve the United Nations Millennium Development Goals - in particular Goals 4 - Child Health, 5 - Maternal Health, 6 - Combating HIV and other diseases. UNITAID's funds are disbursed to international partners working in global health and health commodities procurement, such as the William J. Clinton HIV/AIDS Initiative (CHAI) and UNICEF.

UNITAID is able to commit to long-term projects that can impact the market for health commodities because its funds primarily come from sustainable and predictable sources like the 'air tax'. UNITAID’s model is based on long-term funding commitments and the purchase of high volumes of medicines and diagnostics. This helps stimulate increased production, which creates economies of scale that drive prices down. In turn, this means that UNITAID and its partners can provide more medicines and treatments with the same budget. For example, the 60% price reductions obtained for key paediatric AIDS medicines since November 2006 have enabled three times as many HIV-positive children to be treated for the same amount of money.

In addition, a key goal of UNITAID is to drive the development of new medicines that are better adapted to patients’ needs. An example of this is, fixed-dose combination (FDC) treatments that combine several medicines into one pill, rather than several tablets a day.