AbstractCytokines are produced by a variety of cells and have numerous of overlapping activities. There is increasing evidence that cytokines play a crucial role in the pathogenesis of psoriasis and of other dermatologic diseases. This review summarizes current knowledge as to how the altered cytokine network is involved in the accumulation of inflammatory cells in lesional skin, and how the cytokines are involved in epidermal hyper‐proliferation. The actions of the most important therapeutic compounds, such as corticosteroids, dithranol, cyclosporine, retinoids, vitamin D3analogues and ultraviolet radiation, on the cytokine system are also discussed. Consideration is given as to how the effects on the production of cytokines and/or cytokine receptors contribute to their therapeutic actio