The article describes a case of systemic scleroderma complicated by a severe nephrotic syndrome after seven years in a 46-year-old patient. Rectal mucosal biopsy and right renal biopsy were performed to clarify the origin of the nephrotic syndrome and because amyloidosis was suspected. Massive amyloid deposits were found in biopsy material, colored with Congo red and studied in normal and polarized light. After processing with guanidine and coloring with Congo red, the material was studied in normal and polarized light; amyloid deposits preserved their congophilia and double refraction during two hours of incubation, which is typical of AL-amyloidosis. The patient was directed to a specialized nephrological department for the treatment of AL-amyloidosis.