The endogenous levels of abscisic acid (ABA), indoleacetic acid (IAA) and of three cytokinins (transzeatin riboside, tZR; isopentenyladenosine, IPA; dihydrozeatin riboside, DHZR) were assayed in suspension cell cultures of male and female plants of asparagus by an immunological method. Assays were carried out on two different materials: -suspension cells of nine different genotypes (four males and five females),:cultured in a growth regulator-free medium; -suspension cells of both male and female plants of a hybrid cultured in five different media.In the first series of assays, significant difference in ABA and cytokinins were found between the nine genotypes but not between the suspension cells of male and female plants even when they belonged to the same hybrid.In the second series, we found highly significant differences in tZR and DHZR levels between cell suspensions cultured in different liquid media; the levels of these endogenous growth regulators were positively correlated with the amount of sucrose in the medium.In comparison with flowers and spears of asparagus, assayed in a previous work (Marziani et al. 1990) suspension cells contained a higher cytokinin level (about 5 fold) and a greatly reduced abscisic acid content (about 175 fold).