Clinical, radiologic, and biochemical studies are presented of a patient with a previously undescribed mucopolysaccharide storage disease. Clinical features include short stuature, hepaosplenomegaly, progressive skeletal deformities of the thorax and spine, granular inclusion in leukocytes, and frequent symptomatic pulmonary infections. Corneal clouding was not present at age 30 months. Mental retardation was not present at age 2 years, but subsequent development is lagging. Radiologic changes of "dysostosis multiplex" involved the skull, spine, ribs, and long and short tubular bones. Mycopolysacchariduria was mild. Enzyme studies on white blood cells and skin fibroblasts revealed virtual absence of the lysosomal hydrolase β-D-glucuronidase. Both parents of the proband and several of his mother's siblings had reduced levels of this enzyme, suggesting an autosomal recessive inheritance. The heterozygous carriers appear clinically and radiologically normal.