Numerous drugs have been associated with destructive thyroiditis (subacute thyroiditis). Sunitinib, a tyrosine kinase inhibitor employed in renal cell carcinoma and gastrointestinal stromal tumors, has recently been linked to destructive thyroiditis with resultant hypothyroidism. We report a patient with transient overt thyrotoxicosis followed by hypothyroidism, apparently related to sunitinib therapy.