We examined the effect of spermine (SPM) and spermidine (SPD) on tumor necrosis factor (TNF)alpha and monocyte chemoattractant protein-1 (MCP-1) secretion from macrophages in various culture conditions, including several protocols of polyamines addition and media supplemented with 0, 1 or 15% fetal bovine serum. TNFalpha secretion was inhibited by SPM or SPD added 18h before stimulation in a concentration-dependent manner. Their effect was directly related to the presence of FBS. When SPM or SPD was added simultaneously to the stimulus, the TNFalpha secretion inhibition was higher than that obtained after pre-treatment. In this case, the effect was inversely proportional to the presence of FBS. The addition of polyamines also inhibited the secretion of MCP-1 in NR8383 cells. We conclude that SPM and SPD inhibited the secretion of inflammatory cytokines TNFalpha and MCP-1 in different ways, depending on culture conditions. In any case, SPM was more effective than SPD.