Shwachman-Diamond syndrome is a rare congenital disorder of unknown etiology. Characteristic abnormalities of this disease include pancreatic insufficiency, skeletal anomalies, growth retardation, recurrent infections, and hematologic abnormalities. Significant morbidity and mortality in these patients result from respiratory infections, which are not well explained on the basis of neutrophil defects. We have had the opportunity to perform an in-depth clinical immunologic and endocrinologic evaluation of a patient with this syndrome with recurrent respiratory tract infections. She was found to have profound humoral immunologic defects, and serum thymulin was absent. In addition, endocrinologic evaluation for growth retardation revealed growth hormone deficiency. The patient responded to treatment with supplemental growth hormone and intravenous gammaglobulin with accelerated growth and cessation of infections. This case is unique in that it links growth hormone deficiency and hypogammaglobulinemia in a non-X-linked manner and may provide the basis for treatment of other patients with this rare syndrome.