Thirteen patients with progressive metastatic renal cell carcinoma were treated with circadian continuous Fluorodeoxyuridine (FUDR) infusions. The drug was delivered according to the variable rate infusion of Hrushesky protocol. All patients had previously received and failed systemic treatment and presented more than one metastatic site. The toxicity was low, however, no objective responses were observed. Despite previous reports of activity of FUDR in metastatic renal cancer, we suggest that the present regimen cannot be recommended in poor prognosis metastatic renal cancer.