The allelic sequence diversity at the HLA-DQB1 locus has been analyzed by polymerase chain reaction (PCR) amplification and sequencing. Fifteen amino acid sequence-defined alleles (one previously unreported) and several silent nucleotide polymorphisms which subdivide these alleles have been identified. Here, we describe the specific amplification of the DQB1 second exon by several different PCR primer pairs and a simple and rapid typing procedure using a panel of 16 horseradish peroxidase (HRP)-labeled oligonucleotide probes capable of distinguishing these DQB1 alleles.