Vasodilatory prostaglandins (PG), contributing to the inflammatory reaction, have gained considerable attention. It is becoming apparent that PG have pharmacological effects traceable to biological activities distinct from smooth muscle relaxation. The data from pharmacological experiments presented here indicate the diverse action of vasodilatory PG analogues in the skin of laboratory animals. Nocloprost, a stable PGE2 analogue, induced erythema in intact skin of rats when applied topically and inhibited in the same dose range an irritant-induced inflammatory reaction in the ears of mice. Iloprost, a stable PGI2 analogue, showed proinflammatory activity after local application by enhancing the leukotriene B4 induced cell infiltration in the skin of mice. The attenuation of the spreading of ear necrosis in mice, on the other hand, indicates an anti-ischemic therapeutic potential of iloprost. Research in the past has elucidated the influence of PG on the vascular component of inflammation, but the role of PG on the cellular component of inflammation is less clear. The diverse effects of PG in skin indicate the need for a better understanding of their local actions.