The role of histidine residues in the chelation of iron at neutral pH by peptides from chicken muscle was investigated to see if it could contribute to the effect of muscle tissue on iron absorption. When ferric iron was chelated by L-histidine at pH 6, the ratio of iron chelated to loss of reactive histidine was 1:1. Chelation of iron by soluble peptides in a digest of insoluble chicken muscle protein was accompanied by a small loss of reactive histidine (4–7%) in the peptides. When peptides were modified with diethylpyrocarbonate, increasing loss of histidine led to a progressive decrease in iron chelation. However, even 89% loss of histidine only reduced iron chelation by 30%. It was concluded that histidyl residues do contribute to iron chelation and therefore could by involved in the promotion of iron absorption by muscle tissue. However, other amino acid residues are likely to be involved.