Because of heterogeneity in the outbred human population, it has been difficult to determine the genetic factors that influence the expressed T cell receptor (TcR) repertoire in autoimmune diseases. To overcome this problem, we have developed a combination of anchored polymerase chain reaction (APCR) and enzyme‐linked immunosorbent assay (ELISA) that can accurately assess TcR V gene frequencies in numerous clinical samples. The results are independent of amplification efficiency, and Vgene usage can be readily analyzed with an ELISA plate reader and associated software. Using this method, the TcR Vβ gene repertoires in peripheral lymphocytes from nine sets of identical twins, normal, concordant or discordant for rheumatoid arthritis (RA), were studied. The TcR Vγ results were compared with TcR Vβ frequencies in the same specimens as determined by APCR‐ELISA and cDNA sequence analysis. The results showed a marked similarity in the TcR Vβ gene repertoires between identical twins, compared to unrelated subjects (p<0.05) whether or not they were concordant or discordant for RA. In contrast, the TcR Vy gene repertoires in the monozygotic twins differed as much as in controls. The data imply that (a) the human TcR Vβ gene repertoire in peripheral blood is genetically controlled, whereas (b) the TcR Vβ gene repertoire is primarily influenced by environmental stimuli, and (c) RA causes no consistent change in TcR Vβ repertoire of peripheral blood. The APCR‐ELISA method, in the context of large‐scale family and population studies, should facilitate a more precise delineation of the genetic factors that regulate human TcR Vβ expression.