We report on a 37-year-old woman with progressive lung and pleural metastases from a right nephroblastoma, who achieved partial remission with recombinant interferon-alpha. The drug was given subcutaneously at a dose of 5 mu. 3 times per week. The response was documented after 3 months of treatment and was maintained for at least 9 months. Although such a response has not been reported in the literature, this case suggests promising activity of recombinant interferon-alpha in relapsed nephroblastoma.