Chemokines play a very important role in inflammation and belong to the family of proinflammatory cytokines. They preferentially act on neutrophiles and have no activity on monocytes and eosinophiles. IL-8 is a member of C-X-C chemokines. The IL-8 level is about 150-times higher in the psoriasis affected skin. It suggests that IL-8 may play an important role in the pathogenesis of psoriasis. The precise mechanism of cyclosporine (CsA) and retinoic acid (RA) effects are not known. The aim of the experiment was to find out CsA effect and RA effect on production of IL-8 by THP-1 cell line. THP-1 cell line was cultivated in completed RPMI-1640 medium and stimulated with LPS. The level of IL-8 was evaluated by human ELISA kits. Student's test was used for statistical analysis. It was found out that CsA inhibits IL-8 production by stimulated THP-1 monocyte cell line in dose dependence course. RA promotes IL-8 production by stimulated THP-1 monocyte cell line in dose dependence course. Preincubation experiments with CsA and RA confirmed the previously found effects of these drugs. CsA did not demonstrate cytotoxic effect on THP-1 cell line. (Fig. 7, Tab. 6, Ref. 17.)