We have studied a panel of DBA/2 T cell clones specific for sperm whale myoglobin (SpW Mb) for TCR (T cell receptor) beta chain gene expression by FACS analysis using the monoclonal antibodies F23.1 and KJ16 specific for the V beta 8 family of the TCR beta chain genes. Within any given specificity group, all the clones tested came from different mice. 10 of 11 I-Ed-restricted SpW Mb-specific T cell clones were F23.1+; 8 of these were also KJ16+. Only one of the three I-Ad-restricted clones tested was F23.1+; this clone was KJ16 negative. This study has demonstrated that I-Ed-restricted T cell clones from DBA/2 mice express members of the TCR V beta 8 family irrespective of the epitopes of SpW Mb recognized. These data suggest an apparent correlation between TCR V beta expression and MHC restriction.