A 3.5-y-old boy of Arabic origin had the clinical features of both type 1 and type 2 fucosidosis, consistent with an intermediate form of the disease. The activity of his leucocyte alpha L-fucosidase was absent. He presented with recurrent sinopulmonary infection and otitis media in addition to paronychia and a periapical dental abscess. Investigation of his systemic immune function did not reveal a significant underlying defect, but subtle abnormalities, particularly of antibody production and secretory IgA, cannot be excluded. The cranial magnetic resonance images showed periventricular and subcortical white matter abnormalities and mild cortical atrophy in addition to globus pallidus changes.