Cytokines are produced by almost any cell and function as important mediators of cell activation, differentiation and proliferation. As more cytokines become available several clinical trials have been performed using cytokines to treat skin diseases. The broadest clinical experience exists with the use of interferons (IFN). Treatment of condylomata acuminata with IFN as an adjuvant therapy appears to be promising. Cutaneous T-cell lymphoma may be treated successfully with IFNαin combination with retinoids and PUVA, respectively. Treatment of malignant melanoma with systemic IFN alone turned out not to be superior to other therapies. Administration of IFNαin AIDS-assoc-iated Kaposi's sarcoma resulted in regression rates of between 20% and 50%. IFNαapplied intralesionally was successful in actinic keratosis, basal and squamous cell carcinomas. Other dermatoses treated with some success with IFN include atopic dermatitis, systemic mastocytosis, lupus erythematosus, Behset's disease, keloids, granulo-matous diseases and leishmaniasis. Interleukin-2 (IL-2) was shown to be of some benefit in treatment of patients with melanoma either as a monotherapy or in conjunction with adoptive immunotherapy using concurrent transfer of either lymphokine-activated killer cells (LAK) or tumour infiltrating lymphocytes (TIL). However, toxicity related to IL-2 administration is severe. According to preliminary reports, tumour necrosis factorα(TNFα) seems to be effective in the treatment of some patients with psoriasis. Early clinical trials indicate growth factors as promising therapeutic agents to improve wound healing. Because of the ability of colony stimulating factors (CSF) to counteract the complications of chemotherapy, in particular bone marrow failure and the consequent susceptibility to infection and bleeding, a considerable number of patients, including those with malignant melanoma and AIDS, seem to be potential candidates for CSF treatment in combination with standard therapies.