Amyloidosis appears to be a rare complication of cystic fibrosis. We discuss three patients with amyloidosis complicating cystic fibrosis to add to the six patients previously recorded. The presenting problem was proteinuria in five patients, thyromegaly in three patients, and hepatosplenomegaly in one patient. The progression of proteinuria to nephrotic syndrome and edema occurred in eight of nine patients and portended a very poor prognosis. The kidneys, adrenal glands, spleen, thyroid gland, liver, heart, and bowel were most frequently involved. Renal involvement is a frequent and devastating complication of amyloidosis in patients with cystic fibrosis.