A 78-year-old woman with renal cell carcinoma and pulmonary metastasis presented with reversible cardiomyopathy induced by gamma(gamma)-interferon. She was treated with gamma-interferon twice a week since November 1996. She presented with severe acute congestive heart failure and gamma-interferon was immediately discontinued in December 1997. Left ventricular fractional shortening was 38% before admission, 12% on admission, and improved to 31% by 40 days after discontinuation of interferon together with administration of diuretics and angiotensin converting enzyme inhibitor. We restarted the same gamma-interferon regimen because it was effective against renal cell carcinoma after 47 days. She has remained well with no significant changes of cardiac function or renal cell carcinoma for almost one year.