In the setting of interleukin-2 (IL-2) administration, tachycardias of ventricular origin are classified as serious, grade IV toxicities, necessitating the discontinuation of therapy. In this report, we describe a patient with renal cell carcinoma who experienced ventricular tachycardia while undergoing treatment with high-dose bolus IL-2. Prophylaxis with sotalol permitted the successful completion of his first cycle of treatment, without any recurrent rhythm disturbances.