Sunitinib is a multiple tyrosine kinase inhibitor of the vascular endothelial growth factor and platelet-derived growth factor pathway and inhibits angiogenesis, cell proliferation, and tumor cell invasion, and stimulates apoptosis. Treatment with sunitinib in first-line metastatic renal cell carcinoma improves progression-free survival and overall survival compared with interferon-α. Crohn's disease is characterized by chronic immune-mediated intestinal inflammation. Although the exact pathogenesis of Crohn's disease remains unknown, the involvement of angiogenesis is acknowledged. It is unknown whether sunitinib interferes with the natural course of Crohn's disease. We describe a patient with metastatic renal cell carcinoma and a history of Crohn's disease who was treated with sunitinib and developed a severe exacerbation of Crohn's disease. After rechallenge with sunitinib, a second exacerbation occurred. We therefore conclude that angiogenesis inhibitors should be administered with care in patients with a history of Crohn's disease.