The expression of Kit, the receptor for stem cell factor (SCF), on bovine peripheral blood cells (PBCs) was examined by using monoclonal antibodies against the bovine Kit protein. Flow cytometric analysis showed that approximately 1.5% of PBCs expressed Kit. In cytospin preparations, the morphology of most Kit⁺ PBCs was similar to that of large lymphocytes. Subsets of Kit⁺ PBCs coexpressed CD3, IgM, and/or CD11b but not CD14 or G1. SCF did not induce the proliferation of Kit⁺ PBCs in vitro. These results indicate that Kit is expressed on subsets of lymphocytes in bovine peripheral blood, but the ligand of Kit, SCF, does not directly induce the proliferation of this cell population.