South Africa is one of the countries most severely affected by HIV/AIDS. At the peak of the epidemic, the government, going against consensus scientific opinion, argued that HIV was not the cause of AIDS and that antiretroviral (ARV) drugs were not useful for patients and declined to accept freely donated nevirapine and grants from the Global Fund. Using modeling, we compared the number of persons who received ARVs for treatment and prevention of mother-to-child HIV transmission between 2000 and 2005 with an alternative of what was reasonably feasible in the country during that period. More than 330,000 lives or approximately 2.2 million person-years were lost because a feasible and timely ARV treatment program was not implemented in South Africa. Thirty-five thousand babies were born with HIV, resulting in 1.6 million person-years lost by not implementing a mother-to-child transmission prophylaxis program using nevirapine. The total lost benefits of ARVs are at least 3.8 million person-years for the period 2000-2005.