A new allele of the human leukocyte antigen C (HLA-C) locus was identified during routine HLA typing of a Chinese hematopoietic stem cell donor in Beijing, China. Sequence analysis of exons 2 and 3 of the HLA-C gene revealed the novel polymorphism. The closest matched allele was HLA-Cw*0710. A comparison of the two alleles showed that HLA-Cw*0743 carried a nucleotide substitution of C to A at codon 99 in exon 3, resulting in an amino acid substitution of serine to tyrosine with no obvious change in protein structure.