T cell trafficking at vascular sites has emerged as a key step in antitumor immunity. Chemokines are credited with guiding the multistep recruitment of CD8 + T cells across tumor vessels. However, the multiplicity of chemokines within tumors has obscured the contributions of individual chemokine receptor/chemokine pairs to this process. Moreover, recent studies have challenged whether T cells require chemokine receptor signaling at effector sites. Here, we investigate the hierarchy of chemokine receptor requirements during T cell trafficking to murine and human melanoma. These studies reveal a non-redundant role for G αI-coupled CXCR3 in stabilizing intravascular adhesion and extravasation of adoptively transferred CD8 + effectors that is indispensable for therapeutic efficacy. In contrast, functional CCR2 and CCR5 on CD8 + effectors fail to support trafficking despite the presence of intratumoral cognate chemokines. Taken together, these studies identify CXCR3-mediated trafficking at the tumor vascular interface as a critical checkpoint to effective T cell-based cancer immunotherapy.