Intestinal tract involvement by primary systemic amyloidosis is frequent but usually asymptomatic. Ischemic colitis caused by amyloid infiltration of wall blood vessels can occasionally be observed. We report a 62-year-old female with primary systemic amyloidosis who presented with intestinal obstruction caused by ischemic stricture of the sigmoid colon, secondary to submucosal amyloid deposition. The patient was successfully treated with surgical resection followed by high-dose chemotherapy and hematopoietic stem-cell transplantation. The clinical manifestations and differential diagnosis of gastrointestinal involvement of primary systemic amyloidosis, as well as its current treatment, are discussed.