DNA double-strand breaks (DSB) are the most dangerous damage to genetic material caused by ionizing radiation and some chemical agents. Nonrestored DSB lead to chromosomal rearrangements, genetic instability, and cell death. On the other hand, DSB normally occur in cells in the course of normal gene functioning. DSB repair not only protects cells from adverse consequences and maintains stability of genetic material but is directly involved in the most important processes of cell life, such as meiosis and humoral immunity in vertebrates. The diverse mechanisms of homologous and nonhomologous recombination underlie DSB repair. In this respect, yeast are the best-studied object. In this review, genetic control and molecular models of the recombination DNA DSB repair in Saccharomyces cerevisiae are considered. Evidence has accumulated that indicates the higher eukaryotes retained the basic set of the repair pathways characteristic of bacteria and lower eukaryotes. However, different repair mechanisms predominate in yeast as compared to higher eukaryotes. Therefore, the results obtained in yeast experiments may be applicable to higher eukaryotes.