A variety of antiangiogenic agents are currently available for the treatment of renal cell carcinoma. With these exciting new therapeutic agents comes the challenge of elucidating useful biomarkers to monitor patients receiving these therapies. Although many patients benefit from antiangiogenic therapies, it is often by achieving stability of their disease. Thus, development of noninvasive biomarkers of disease response and relapse is a crucial objective to aid in the management of patients. The current technologies being explored in this field include circulating plasma proteins, cells, and nucleic acids and novel imaging techniques. Surrogate markers of angiogenesis could help with selecting patients for therapy, determining optimal dosing of therapy, deciding whether to change therapy, and assessing appropriate salvage therapy.