AbstractBackground: Malignant melanoma is the type of skin cancer with the greatest rise of registered incidence and with the greatest mortality. It is well known that ultraviolet radiation can cause melanoma, but there has been much uncertainty regarding the exact spectrum of radiation that initiates the carcinogenesis. Purpose: To study what is known regarding the roles of UVA and UVB in melanoma carcinogenesis. Method: Literature study based on searches in the PubMed database, for publications concerning malignant melanoma and UVA and UVB, sun beds and sunscreen. Results: Both UVB and UVA can damage human melanocyte DNA in vivo and in vitro. Of the mutations in human melanomas, some are thought to be UV-specific, but there is disagreement as to whether UVB or UVA causes these mutations. Still, many mutations are of unknown cause. Animal studies show different results. The results of epidemiological studies points to an association between UVA and melanoma. There seems to be an association between sun bed use and melanoma, especially when using sun bed before the age of 30-35. Studies concerning sunscreen and melanoma risk show highly varying results. Conclusion: Ultraviolet radiation can cause melanoma. It is difficult to conclude about the relative roles of UVA and UVB in the carcinogenesis, but both seems to be of significance.