Gaucher disease (GD) is an autosomal recessive glycolipid storage disorder, due to deficiency of the lysosomal enzyme glucocerebrosidase, leading to accumulation of the substrate glucocerebroside in the cells of the macrophage-monocyte system. Patients with GD have alteration in their immune system and impaired microbicidal capacity of mononuclear phagocytes. It has also been demonstrated that monocyte dysfunction may correlate with the plasma glucocerebrosidase concentrations. Tuberculosis (TB) is a major public health problem in developing countries. Pleural TB is one of the most common forms of extra-pulmonary TB. Since immune system can be impaired due to the deficiency of glucocerebrosidase in various ways, TB can be observed in patients with GD especially when left untreated. Cytopenia(s) is also general finding in untreated Gaucher patients, and they may be observed most frequently due to the infiltration of the bone marrow with Gaucher cells together with the additional factor of splenomegaly. We herein present a case of an adult patient with heterozygous untreated GD1, who developed pleural TB i complicated by ipsilateral pulmonary fibrosis. Before his admission to our clinic, pleurectomy operation was performed and 4-drug combination anti-TB therapy was initiated including isoniazid, rifampicin, ethambutol and pyrazinamide. Fever complaint was disappeared with anti-TB treatment but he also had fatigue and pain. After initiation of enzyme replacement therapy in addition to anti-TB treatment, clinical and hematological improvement was observed. To our knowledge, this is the first reported case of GD1 with pleural TB. (C) 2015, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.