e16118 Background: Approximately one third of patients with renal cell carcinoma (RCC) will develop bone metastases during the course of their disease. Previous studies suggest that the rate of skeletal related events (SREs) in patients with metastatic renal cell carcinoma is high, and that bisphosphonate therapy can lower the rate of SREs. We conducted a retrospective review of patients with metastatic renal cell carcinoma and bone metastases seen at our academic cancer centre. Methods: After approval by the Research Ethics Board, a retrospective review of all patients seen at the London Regional Cancer Centre with a diagnosis of RCC between January 2006 and December 2008 was performed. Data points collected included the number of patients with bone metastases, number of SREs, length of hospital stay, and treatments related to SREs. A SRE was defined as one of the following: pathologic fracture, spinal cord compression, radiotherapy or surgery to bone, or hypercalcemia in the presence of bone metastases. Results: 196 patients with metastatic RCC were identified. Of these, 63 (32%) had bone metastases. 75% of these patients with bone metastases received medical therapies including sunitinib, sorafenib or temsirolimus. 66% of patients received at least one dose of bisphosponate therapy. Common sites of metastases were vertebra (66%), pelvis (50%), and femur (42%). Of those with bone metastases, 61 (95%) experienced at least one SRE. 42% sustained a pathologic fracture; 28% suffered a spinal cord compression or cauda equina syndrome; 22% had surgery for bone metastases; 87.5% required radiotherapy and 27% had hypercalcemia. 40% of patients were hospitalized due to an SRE, and the mean length of hospital stay was 21 days (range 1–120 days). Conclusions: Despite significant recent improvements in the overall care of RCC, and expansion of the number of therapeutic options, bone metastases and consequent SREs continue to cause significant morbidity. These SREs come with frequent and prolonged hospitalizations. Our rate of SREs is actually higher than that documented in the placebo arm of a randomized trial of a bisphosphonate in RCC from the pre-tyrosine kinase era. Bone-related morbidity in mRCC remains a clinical problem with a significant unmet medical need. [Table: see text]