Base excision repair (BER) is the fundamental pathway responsible for the elimination of damaged DNA bases and repair of DNA single-strand breaks generated spontaneously or produced by DNA-damaging agents. Among the essential enzymes that are required to achieve the BER reaction is DNA polymerase beta (pol β), which has been regarded as a potential therapeutic target. More than 60 pol β-inhibitors have been identified so far; however, most of them are either not potent or not specific enough to become a drug. In this article we compile an essential knowledge base regarding the structures, the modes of inhibition and the activities of these pharmacologically interesting molecules.