DNA repair is a prominent member of the nuclear transactions triad (replication, transcription, and repair). Sophisticated mechanisms govern the cellular process of decision-making (to repair or not to repair, to proceed with cell cycle or not and, eventually, to let the cell survive or die) and the temporal and spatial distribution of the DNA repair activities. UV radiation is a very common and virtually unavoidable mutagen whose carcinogenic potential seems to accumulate over time. Various strategies have been developed to avoid or decrease UV damage to cellular DNA, based on prevention of exposure as well as on post-irradiation measures. It is, however, important to acknowledge that the individual capacity for DNA repair varies during the life of the individual and must, therefore, be assessed so as to determine whether the individual is coping with environmental UV damage. Assessment of individual repair capacity might greatly modify the existing therapeutic strategies for common cancers and ought to become a routine part of health prophylaxis.