The influence of E2 and PGF2 alpha-prostaglandins on the level of cAMP in non-stimulated and stimulated by lectins lymphocytes has been studied. PGE2 increased clearly the level of intracellular cAMP but did not increase the number of blastic cells in the culture. PGF2 alpha did not change any of these factors. Prostaglandins (E2 and F2 alpha) did not influence the level of cAMP in lymphocytes affected previously by lectins (PHA and Con A), except Con A+PGF2 alpha scheme. PGE2 (and partly PGF2 alpha and lectins are supposed to act competitively in relation to the same receptor of lymphocyte cells.