Selective base pairing of the four canonical nucleobases is fundamental for the integrity of the genetic system. Information loss associated with DNA damage is a constant challenge and in response, organisms have evolved specialized defence systems consisting of DNA repair and lesion tolerance. DNA repair requires the action of different lesion recognition proteins such as lesion-specific glycosylases and DNA endonucleases. Lesion tolerance is established by special translesion synthesis (TLS) polymerases, which are able to bypass lesions during replication. In the past decade a large number of structures of repair proteins and TLS polymerases in complex with DNA containing individual lesions provided detailed insight into the chemistry of DNA repair and TLS. This review summarizes recent structural results.