Introduction: GD is the commonest lysosomal storage disease worldwide. The majority of the patients have Type1 GD which is the non-neuronopathic form of disease. There are data of increased risk of cancer in GD patients, such as: multiple myeloma and other haematological malignancies, hepatocellular carcinoma and renal carcinoma. Factors of cancerogenesis in GD are accumulation of bioactive lipids, alternatively activated macrophages, immune dysregulation, genetic modifiers underlying the GD, splenectomy and enzyme replacement therapy. Extra-osseous soft tissue masses are described in GD patients, like localised deposition od Gaucher macrophages (Gaucheroma). To the best of our knowledge, no other case of extra-osseous soft tissue sarcoma in association with GD has been described in literature. To present very rare case of high grade leiomiosarcoma in association with Gaucher disease (GD). Case report: The case concerns 81 years old female with leucopenia and thrombocytopenia since year 2000. In 2014 she was diagnosed with undifferentiated pleomorphic sarcoma with prominent inflammation on her thigh, which was not completely surgically removed. She was diagnosed with leucopenia, thrombocytopenia and splenomegaly in 2014 on control examination. Bone marrow biopsy was performed and histologically and immunohistochemically was diagnosed GD. The diagnosis was confirmed by enzyme activity test. In 2018 revision of pathohistological finding of thigh tumour was performed. High grade leiomiosarcoma was diagnosed. She is alive and refuses any treatment. Conclusion: GD is rarely diagnosed in older age. All soft tissue masses in GD should be carefully examined because of increased risk of cancer in GD patients.