BACKGROUND: The aim of our study was to determine whether the presence of bone metastases affects outcomes in patients with metastatic clear-cell renal cell carcinoma (m-ccRCC) receiving sunitinib. PATIENTS AND METHODS: We reviewed the charts of all patients in four academic centers in Belgium and France who started first-line sunitinib (50 mg/day; 4 weeks on and 2 weeks off) between January 2005 and December 2008. Data were collected on known prognostic factors for metastatic renal cell carcinoma and metastatic sites. Response and progression were evaluated by computed tomography scan (according to RECIST). RESULTS: Two hundred twenty-three patients were identified. With a median follow-up of 40 months, median progression-free survival (PFS) and median overall survival (OS) were significantly shorter in patients with bone metastases than in those without: respectively, 8.2 versus 19.1 months (P < 0.0001) and 19.5 versus 38.5 months (P < 0.0001). On multivariate analysis, taking on account platelet count, Eastern Cooperative Oncology Group performance status, number of metastatic sites, neutrophil count, corrected serum calcium, time from diagnosis to systemic treatment, and the presence of bone metastases, bone metastasis was the independent variable most significantly associated with poor PFS (P < 0.0001) and OS (P = 0.001). CONCLUSION: The presence of bone metastases in m-ccRCC patients has a significant and clinically relevant negative impact on outcome on sunitinib.