A 6-month-old female infant presented with severe psychomotor retardation, coarse facies, gingival hyperplasia, thick skin, restricted joint movements and radiological features suggestive of the Hurler syndrome. Her urine showed no excess excretion of mucopolysaccharides. I-cell disease was suspected from the onset of clinical features in early infancy, the subsequent progress and the absence of mucopolysacchariduria. Marked elevation of the activity in serum of three lysosomal enzymes confirmed the diagnosis. This patient had repeated convulsions, a feature not previously reported in this condition. This is the first case report of I-cell disease from India.