We report on a family ascertained because of sibs affected with nasopharyngeal carcinoma. Other relatives had aplastic anemia or other malignancies and most were born of consanguineous parents. Epstein-Barr virus has been strongly implicated in the pathogenesis of nasopharyngeal carcinoma. It has also been suggested as a cause of aplastic anemia and other neoplasms. We postulate that this extensive German-Mennonite family has a heritable defect in the immune response to Epstein-Barr virus making its members at excessive risk for a number of different malignancies. This immunologic predisposition may be HLA associated and appears to be inherited as an autosomal recessive trait.