Human Vγ9Vδ2 T cells play a crucial role in early immune response to intracellular pathogens. Moreover, in brucellosis, these cells are drastically increased in the peripheral blood of patients during the acute phase of infection. In vitro, Vγ9Vδ2 T cells are capable of inhibiting Brucella growth and development through a combination of mechanisms: 1) cytotoxicity, 2) macrophage activation and bactericidal activity through cytokine and chemokine secretion, and 3) antibacterial effects. We previously described that antibacterial factors were found in supernatants from activated Vγ9Vδ2 T cells. In this study, we show that Vγ9Vδ2 T cells express the human cathelicidin hCAP18 and its mature form, known as LL-37, is released upon activation of Vγ9Vδ2 T cells. We also show that LL-37 has an antibacterial effect on Brucella suis. Overall, our results demonstrate that LL-37 is a soluble factor responsible for a part of the bactericidal activity of Vγ9Vδ2 T cells.