SummaryThe monovalent and divalent anion transport in red blood cells from patients with cystic fibrosis and controls is not significantly different. The protein pattern of the erythrocyte membrane, as seen by sodium dodecyl sulfate‐polyacrylamide gel electropherograms, is similar in cystic fibrosis and control red blood cells. The 2,3‐diphosphoglycerate content of the investigated cystic fibrosis red blood cells is normal.AbbreviationsDIDS, 4,4'‐diisothiocyanate‐1,2‐diphenylethane‐2,2'‐disulfonic acidCF, cystic fibrosis2,3‐DPG, 2,3‐diphosphoglycerateSDS, sodium dodecyl sulfate