The expression of 13 different alpha and beta V gene segments of the T cell receptor for antigen (TCR) was examined, using V gene-specific MoAbs, on human peripheral blood T lymphocytes from 32 healthy Japanese subjects. In addition, to examine associations between TCR V gene products and HLA alleles, the HLA class I and class II types of all subjects were serologically determined. The reactivities of the anti-TCR V-specific MoAbs were, with some significant exceptions, similar to those previously described in healthy Caucasian subjects. We found a non-random V gene usage as well as a statistically significant bias of the expression of eight V beta gene products towards the CD4+ subpopulation, and a significant skewness in the usage of V alpha 12 towards the CD8+ population. Some subjects showed increased reactivities (above 10%) of certain MoAbs, mainly in the CD8+ subpopulation. We found no distinct correlation between any certain HLA class I or II allele and TCR V gene usage in the CD8+ or CD4+ subpopulations, respectively. In conclusion, the pattern of anti-TCR V-specific MoAb reactivities found in CD4+ and CD8+ subsets of peripheral blood lymphocytes of healthy Japanese subjects was in general found to match that previously described in healthy Caucasian subjects.