Inbred mice infected with Leishmania major promastigotes display two different courses of leishmaniasis: resistant strains develop self-healing local sores, while susceptible strains show progressive systemic disease with lethal outcome. Resistance predominantly correlates with the production of T helper type 1 (TH1) lymphokines and susceptibility with production of TH2-type lymphokines. Here, we analyzed whether this TH phenotype difference correlates with expression of particular T cell receptor V beta chains. Our results show that T cells expand strongly during infection in all groups of mice and invariantly express the same V beta gene families as prior to infection. Our data indicate that TH1 and TH2 cells use similar V beta gene families, and argue against the engagement of a restricted set of V beta by dominant determinants associated with L. major.