Immunological investigations in malignant melanoma have demonstrated the important role of immunological defence mechanisms in the control of tumour growth and tumour spread. On the basis of the different test systems for investigation of immunecompetence and tumourspecific immunity it was possible to demonstrate that patients with melanoma, especially of clinical stages II and III, have a weak, sometimes an anergic immune reaction against their own tumour. The information obtained from in vitro and in vivo studies in human on tumour immunity formed the rational basis for immunotherapy in malignant melanoma. Increasing evidence suggests that active non-specific immunotherapy and, especially, active specific immune-stimulation with inactivated melanoma cells can delay the appearance of distant metastases and result in an improved survival rate for patients with involved regional lymph nodes. At present the use of involved chemotherapy is mostly confined to patients with disseminated malignant melanoma. The most extensively used chemotherapeutic agent for treatment of melanoma is the DTIC (dimethyl-triaceno-imidazole-carboxamide). The objective response rate with this monotherapy has been reported to be up to 25%. Nitrosoureas (BCNU, CCNU, MECCNU) have also been widely used and have brought clinical responses similar to DTIC. Experimental studies in animal models and investigation in human have demonstrated that chemotherapy can be combined successfully with immunotherapy with a potential additive, perhaps synergistic, effect.