Since 1997 when the American Academy of Pediatrics (AAP) issued revised guidelines for the prevention of poliomyelitis, substantial progress in global eradication of poliomyelitis has occurred and the use of inactivated poliovirus vaccine (IPV) has increased considerably in the United States with a corresponding decrease in the use of oral poliovirus vaccine (OPV). Surveys indicate that the majority of physicians now routinely immunize children with the sequential IPV-OPV or IPV-only regimens. Nevertheless, vaccine-associated paralytic poliomyelitis (VAPP) continues to occur, albeit infrequently, in children who have received the OPV-only regimen and their contacts. To reduce further the risk of VAPP, the AAP now recommends that children in the United States receive IPV for the first 2 doses of the polio vaccine series in most circumstances. Exceptions include a parent's refusal to permit the number of injections necessary to administer the other routinely recommended vaccines at the 2- and 4-month visits. Either IPV or OPV can be administered for the third and fourth doses. Assuming continuing progress toward global eradication, a recommendation of IPV-only immunization for children in the United States is anticipated by 2001.