This paper investigates the association between social support, disclosure of HIV/AIDS, and odds of initiating combination antiretroviral drug therapy in its first years on the market. Data are drawn from the first three rounds of the Community Health Advisory and Information Network (CHAIN) survey, collected between 1994 and 1997. CHAIN documents service needs and rates of service utilization among a representative sample of persons with HIV/AIDS in New York City. A two-step logistic regression estimated associations between (1) perceived social support and use of combination antiretroviral therapy, and (2) the interaction between concealing HIV/AIDS and perceived social support. Results offered evidence that the positive association between social support and use of highly active antiretroviral treatment (HAART) and other combination antiretroviral therapies is contingent upon disclosure of HIV status within the household or among friend and acquaintance networks. A positive association between social support and odds of using combination therapy was only observed among those who disclosed their HIV status.