Fucosidosis is a rare, autosomal recessive lysosomal storage disorder caused by a severe deficiency of alpha-L-fucosidase. Here we present a 27-month-old male who was referred to us for evaluation of developmental delay, which was first detected at age six months. His past medical history was also remarkable for recurrent pulmonary infections and myoclonic seiures. His family history revealed that he was the first living child from a consanguineous marriage. He had a younger sister who died at five months of age from pneumonia who had facial resemblance to the proband, developmental delay and a congenital heart defect. Physical examination revealed length: 81 cm (25-50p), weight: 10.2 kg (25-50p), and head circumference: 49 cm (50-75p). He had a coarse face, hepatomegaly and generalized spasticity. His initial laboratory examination revealed negative urine screening column chromatography for mucopolysaccharidosis. His X-ray findings were consistent with mild form of dysostosis multiplex. Based on clinical and laboratory features, fucosidosis was suspected. Fucosidase enzyme activity was zero. In addition to fucosidosis, thyroid function tests indicated primary hypothyroidism. This is, to the best of our knowledge, the fourth case of fucosidosis diagnosed in Turkey.