A 63-year-old man who had had a history of rheumatoid arthritis presented with shock and hemoperitoneum, without a history of trauma. An emergency laparatomy revealed hemoperitoneum and splenic rupture with massive bleeding. Splenectomy was performed. Histopathological examination of the spleen revealed amyloid deposition in the wall of the vessels. Rectal biopsy revealed amyloid deposition in mucosa that indicating amyloidosis was systemic. Histochemical studies showed that amyloid was secondary or AA.