Exposure to DNA-damaging agents invokes biological responses necessary for damage recovery and cell survival. Despite the presence of intact DNA repair pathways, lack of certain other biological pathways has been shown to sensitize cells to DNA-damaging agents' exposure. It is likely that following DNA damage a complex interplay between DNA repair pathways and other biological pathways might be required to ensure cell survival. In this chapter, we describe a high-throughput method for the identification of genes essential for cell survival following DNA damage by using a cell-based assay to measure viability in combination with an RNA interference-based genome-wide screening experiment.