BACKGROUND The technique of allele-specific polymerase chain reaction (PCR) amplification has been adapted for DNA-based human platelet alloantigen typing. METHODS Sequence-specific primers were used to discriminate between the alleles encoding the six major human platelet alloantigens in a series of patients and normal blood donors. RESULTS This technique allows the direct determination of platelet antigen genotypes from genomic DNA after PCR amplification and agarose gel electrophoresis. It offers significant advantages over previously described techniques for alloantigen identification, as the additional analytical steps of restriction enzyme digestion or dot blot hybridization are not required. The results obtained with this technique correlated precisely with those derived from serologic typing and allele-specific oligonucleotide hybridization. CONCLUSIONS The use of allele-specific PCR for platelet alloantigen typing should facilitate the development of DNA-based typing in other regional blood centers and clinical laboratories.