Pigs express two globin genes of beta-type, the epsilon- and chains during their embryonic stage. With the alpha- and epsilon-chains they form four embryonic hemoglobins. We describe here in detail the experimental procedures for sequencing the epsilon- and chains from the pig (Sus scrofa domestica) and we discuss the data with respect to their special functional properties. From the components Gower I and Heide I, we obtained all embryonic chains by chromatography on CM-Cellulose. The sequence of the tryptic peptides of the beta-type chains was established by automatic Edman-Begg degradation. They were aligned by comparison with the corresponding human chains. The epsilon-chains from man and pig differ in 20 positions, porcine and epsilon-chains only in 4 positions. Up to now these have only been found in pigs. A fetal hemoglobin (gamma-chains) was not observed. As a result of this work the sequences of all peptide chains of pig's hemoglobin are determined.