Interferon γ (IFNγ) is an important modulator of immune responses acting on multiple cell types, such as lymphocytes, macrophages or endothelial cells. We investigated the effects of recombinant bovine IFNγ on bovine umbilical vein endothelial cells (BUVEC) for the level of polymorphonuclear neutrophil cell (PMN)- and peripheral blood mononuclear cell (PBMC)-adhesion as well as the gene transcription of endothelial cell-derived adhesion molecules (E-selectin, P-selectin, VCAM-1, ICAM-1), chemokines (CXCL1, CXCL8, CXCL10, CCL2, CCL5), GM-CSF, iNOS and COX-2 in comparison to TNFα-stimulation. IFNγ strongly induced PMN and PBMC adhesion on BUVEC involving CD4⁺, CD8⁺ and γδ-TCR⁺ (WC1⁺) lymphocytes. Furthermore, IFNγ-stimulation led to a strong upregulation in the transcription of VCAM-1, ICAM-1, CXCL10 and CCL2 genes and to a low to moderate increase in the E- and P-selectin, CXCL1, CXCL8, CCL5, COX-2 and iNOS gene transcripts, but failed to enhance GM-CSF gene transcription. These results indicate that IFNγ can be considered an important activator of endothelial cells in the bovine system, most probably by influencing the outcome of inflammatory responses through selective upregulation of immunoregulatory molecules.