The polyelectrolyte Magnafloc M22S and Superfloc A150 were tested in the process of obtaining protein preparation from pea cv. Piast. Additionally, preparations were precipitated by polyelectrolyte with calcium ions. The total protein, true protein, amino acid content, electrophoretic and chromatographic separation of protein of the obtained preparations were compared with concentrate precipitated at the isoelectric point of protein. Total protein content (N × 6.25) ranged from 80 to 89%, whereas true protein constituted 75–85% of total protein. EAAI (essential amino acid index) varied from 76 to 87 and the highest value was obtained in concentrate from Magnafloc M22S with calcium ions flocculation. There were no significant differences in hydrophilic amino acid content. These values of acid preparation (PA), Magnafloc M22S preparation (PM), Magnafloc M22S with calcium ions preparation (PM1), Superfloc A150 preparation (PS) and Superfloc A150 with calcium ions preparation (PS1) were 57.9, 56.3, 57.9, 57.1, 56.1 and 56.1%, respectively. Gel electrophoresis of protein of all concentrates (except PM1) showed similar molecular weight subunit patterns ranging from 53 to 106 kDa. The results indicate that the coagulant used influence protein quality of peas concentrates.