The hemoglobin of the European marmot Marmota marmota marmota has been found to consist of only one component. In this work, we are presenting its primary structure. The globin chains have been separated by high performance liquid chromatography and the sequences have been determined by automated Edman degradation of the chains and their tryptic peptides, as well as of the peptide obtained by acid hydrolysis of the Asp-Pro bond in the beta-chains. In the alpha-chains we have found 13 and in the beta-chains 34 exchanges compared with the human alpha- and beta-chains, respectively. The amino acids which are substituted in the alpha-chains are not involved in any contacts, whereas in the beta-chains, one exchange involves a heme contact, two alpha 1/beta 1- and one alpha 1/beta 2-contacts. The functional and evolutionary aspects of these findings are discussed.