This study evaluates the consultation needs of clinicians who provide perinatal human immunodeficiency virus (HIV) care in the United States. The Perinatal Hotline (1-888-448-8765) is a telephone consultation service for providers who treat HIV-infected pregnant women and their infants. Hotline calls were analyzed for demographics about callers and their patients and information about consultation topics. There were 430 calls to the hotline from January 1, 2005, through June 30, 2006. Most calls (59.5%) were related to pregnant patients; 5.1% of the calls pertained to women currently in labor. The most common topic was HIV care in pregnancy (49.1%), particularly antiretroviral drug use (42.1%). HIV testing was discussed in 21.9%, and intrapartum treatment was discussed in 24.0%. Callers most often requested help choosing antiretroviral drug regimens; many of the discussions were about drug toxicities and viral resistance. Although the hotline received few calls about women in labor, the need for these consultations is expected to increase with the expanding use of rapid HIV testing. Access to 24-hour consultation can help ensure that state-of-the-art care is provided.