The incidence of both renal cell carcinoma (RCC) and obesity are steadily rising in Western societies. Recent studies have established that obesity is a significant risk factor for the development of several malignancies, including RCC. However, the mechanisms underlying this relationship remain to be fully elucidated. We review herein the epidemiological links between obesity and RCC, the potential mechanisms by which obesity can influence RCC development and progression, and the special considerations related to the treatment of obese patients with RCC.