Background: Most textbooks of dermatology attribute basal-cell carcinoma (BCC) chiefly to ultraviolet radiation (UVR), especially that from the sun. Objectives: To present evidence in favor of and against this concept. Patients/Methods: Review of the literature. Results: That UVR truly is capable of inducing BCC in a person susceptible genetically is exemplified by xeroderma pigmentosum (XP), but genetics alone can bring about an efflorescence of BCCs, sometimes countless of them, in persons with the nevoid basal cell carcinoma syndrome (NBCCS). Outside the setting of XP and NBCCS, however, the evidence that UVR chiefly is responsible for any type of BCC, including the noduloulcerative, is not compelling. BCC presents itself usually as but a few lesions and some of those occur on a part of the skin that is covered. Furthermore, no correlation has been found between prominent solar elastosis in the dermis and a BCC in the very same section of tissue. Conclusions: On the basis of all that is known currently, UVR has not been shown to be a major factor in the cause of BCC of any type.