BACKGROUND: Everolimus (RAD001) is an orally administered inhibitor of the mammalian target of rapamycin (mTOR), a therapeutic target for metastatic renal cell carcinoma. We did a phase III, randomised, double-blind, placebo-controlled trial of everolimus in patients with metastatic renal cell carcinoma whose disease had progressed on vascular endothelial growth factor-targeted therapy. METHODS: Patients with metastatic renal cell carcinoma which had progressed on sunitinib, sorafenib, or both, were randomly assigned in a two to one ratio to receive everolimus 10 mg once daily (n=272) or placebo (n=138), in conjunction with best supportive care. Randomisation was done centrally via an interactive voice response system using a validated computer system, and was stratified by Memorial Sloan-Kettering Cancer Center prognostic score and previous anticancer therapy, with a permuted block size of six. The primary endpoint was progression-free survival, assessed via a blinded, independent central review. The study was designed to be terminated after 290 events of progression. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00410124. FINDINGS: All randomised patients were included in efficacy analyses. The results of the second interim analysis indicated a significant difference in efficacy between arms and the trial was thus halted early after 191 progression events had been observed (101 [37%] events in the everolimus group, 90 [65%] in the placebo group; hazard ratio 0.30, 95% CI 0.22-0.40, p<0.0001; median progression-free survival 4.0 [95% CI 3.7-5.5] vs 1.9 [1.8-1.9] months). Stomatitis (107 [40%] patients in the everolimus group vs 11 [8%] in the placebo group), rash (66 [25%] vs six [4%]), and fatigue (53 [20%] vs 22 [16%]) were the most commonly reported adverse events, but were mostly mild or moderate in severity. Pneumonitis (any grade) was detected in 22 (8%) patients in the everolimus group, of whom eight had pneumonitis of grade 3 severity. INTERPRETATION: Treatment with everolimus prolongs progression-free survival relative to placebo in patients with metastatic renal cell carcinoma that had progressed on other targeted therapies.