Silicosis is a chronic, progressing disease of the respiratory system. The aim of this paper was to describe a case of silicosis coexisting with not typical plasmocytoma. Silicosis was diagnosed in a 62-year old woman, after an 8-year employment as a grinder. The patient has suffered from progressing weakness, fatigue, and dyspnea for 2 years. The increased leucocytosis (18-20,000) and moderate lymphocytosis were found in laboratory tests. The patient was admitted to the hospital in a very serious condition, with fever and progressing insufficiency of the respiratory and circulatory systems. Following computed tomography (CT), tumorous silicosis was diagnosed in the Department of Internal and Occupational Diseases. After three months, the increased level of the whole number of serum proteins (until 90 g/l) was found for the first time together with few places of osteolysis in the x-ray cranium picture. The plasmocytoma infiltrations were found in the post-mortem lung examination. The described case seems to be interesting in view of a possible induction of monoclonal gammopathy by silicosis.