A 74-year-old man with metastatic renal cell carcinoma and a history of cardiac failure was treated with sunitinib malate. MUGA echocardiography could not detect a relevant change in the ejection fraction although the clinical situation of the patient worsened dramatically. The only parameter to hint at the deteriorated cardiac function was plasma N-terminal pro-brain natriuretic peptide (BNP). Finally, the patient died after only one cycle of sunitinib treatment. We propose to prospectively include BNP for the early detection of cardiovascular decompensation in high-risk patients. Future studies concerning the relevance of BNP in drug-related cardiotoxicity are urgently needed. Copyright (C) 2010 S. Karger AG, Basel