Transmission of HIV in the Dominican Republic occurs primarily through heterosexual contact. As part of a continuing strategy to prevent and contain the spread of HIV infection, the Ministry of Health of the Dominican Republic established an integrated package of interventions to reduce HIV mother-to-child transmission that was initiated on May 15, 2000. The program was designed to be implemented in 3 phases. The 1st phase included 4 mother and child hospitals; the 2nd phase included 8 mother and child health institutions in Santo Domingo, the capital of the Dominican Republic, and 7 additional mother and child hospitals. The 3rd phase will include the remaining 12 mother and child health care institutions of the Dominican Republic. Evaluation of the 1st year of this program, involving 8 hospitals and >40,000 pregnant women, identified specific benefits and limitations. Low numbers of voluntary counseling sessions (6528/42,666 = 28%) and inadequate number of HIV rapid tests (23,067/42,666 = 54%) were the 2 main obstacles encountered. From the 23,067 pregnant women tested, 581 (2.5%) were HIV positive. Advantageous aspects included the successful administration of antiretroviral treatment to 89% (164/185) of the mothers and 98% (183/186) of the children. Cesarean section was performed in 67% (124/185) of the HIV-positive pregnant women, and infant formula was dispensed to 47% (87/186) of all cases. These findings demonstrate the feasibility of implementing a large-scale program to prevent mother-to-child transmission in a developing country.