Interleukin-6 (IL-6) is a pleiotropic immunomodulatory cytokine produced by various types of cells, including melanoma cells. IL-6 plays a major role in the pathogenesis and development of malignancies. It promotes tumour growth by inhibition of apoptosis and induces tumour angiogenesis. IL-6 is deregulated in many types of cancers, and increased serum concentration of IL-6 has been correlated with a worse prognosis in patients with different cancers, including melanoma. Several serum cytokines including IL-6 play an important role in the development and progression of melanoma; however, the specific biological functions of IL-6 in progression of melanoma are unknown. In this review, we present studies on cell cultures and mouse models and summarize published clinical studies on IL-6 and melanoma.