Two brothers, aged 40 and 38 years, suffered from dysplastic features, coarse facies, bone and skeletal abnormalities, deformities of spine, and joint impairments. Body heights were 168 and 164 cm, respectively. Enlargement of liver and spleen, cardiac insufficiency, marked corneal clouding, and hernias were absent. Both patients had signs of cervical and lumbar radiculopathy and cervical myelopathy (tetraspastic syndrome). Vacuoles, acid phosphatase-positive granules, and metachromatic inclusions were found in peripheral lymphocytes; granulocytes and monocytes contained azurophilic hypergranulation. By electron microscopy, clear membrane-bound vacuoles were noted in lymphocytes (but not in neurtrophils), fibroblasts, Schwann cells, mural cells of the vasculature, and epidermal cells. Leukocytes, urine, and cultured skin fibroblasts revealed a deficiency of arylsulfatase B (N-acetylgalactosamine 4-sulfate sulfatase). The 6-year-old daughter of one of the patients has an intermediate level of this enzyme. Fibroblasts exhibited a constant intracellular accumulation of 35S-labeled mucopolysaccharides. The urine of one of the brothers showed an abnormal mucopolysacchariduria; in both, the presence of urinary dermatan sulfate could be demonstrated. These findings conform to the mild B variant of Maroteaux-Lamy syndrome with high longevity.