Three cases of acute flaccid paralysis (AFP) associated with circulating vaccine-derived poliovirus (cVDPV) isolates were reported in the Philippines during March 15-July 26, 2001. The first case-patient, a child aged 8 years from northern Mindanao island (500 miles south of Manila) who had received 3 doses of oral polio vaccine (OPV), had onset of paralysis on March 15. A second child, aged 3 years from Laguna province on Luzon island (60 miles south of Manila) who had received 3 OPV doses, presented with signs of meningitis but no paralysis on July 23. A third child, aged 14 months from Cavite province (25 miles from Manila and 45 miles north of Laguna province) who had received 2 OPV doses, had onset of paralysis on July 26. No patients had traveled outside of their province of residence since birth. Characterization of isolates from the three patients revealed type 1 polioviruses derived from Sabin vaccine strain type 1, with a 3% genetic sequence difference between Sabin 1 vaccine and vaccine-derived poliovirus (VDPV) isolates. The three polioviruses are not identical but are closely related (>99% sequence homology); they also appear to share an identical recombination site with a nonpolio enterovirus in the noncapsid region of the genome.