Alpha 1 antitrypsin phenotypes and serum levels are presented for a family in which two brothers have Weber Christian disease and alpha 1 antitrypsin (PI) Z phenotypes. Clinical histories are described for these two men. A younger brother has the PI Z phenotype but does not have the disease, indicating that additional genetic and/or environmental factors contribute to the pathogenesis of Weber Christian disease. However, the two cases described provide additional evidence for a relationship between alpha 1 antitrypsin deficiency and the development of symptoms.