Skeletal pain and the resulting skeletal complications are common in Gaucher disease. The patients therefore usually receive symptomatic treatment and only rarely undergo additional diagnostic procedures. The paper describes the case of a patient with Gaucher disease who had advancing pain in the right knee and femur, which was first attributed to the basic disease. After a pathological fracture of the painful part of the leg, it became evident that the patient suffered from primary bone angiosarcoma. From this case, we learnt that not every skeletal pain in Gaucher disease represents a skeletal manifestation of this disease. Further surgical treatment was made difficult by the thrombocyte dysfunction discovered in the patient.