Replication-dependent or independent DNA lesions induced by DNA damaging agents or radiation have been a useful strategy for cancer treatment. A growing number of novel anti-cancer agents have been designed on the basis of their ability to inhibit DNA repair processes or promote cellular senescence. The functions of DNA helicases in the DNA damage response, replication, or avoidance of cellular senescence suggest that this class of enzymes may be a useful target for the development of a new generation of chemotherapy drugs. Biochemical, cellular and genetic characterization of helicases has proven to be insightful for the delineation of their respective functions and biological roles in pathways of DNA metabolism that confer genomic stability. In this review, we will discuss the rationale for development of helicase inhibitors that might improve chemotherapeutic options for treating cancers. As a guide for the discovery of novel anti-cancer agents, the human helicases implicated in disorders associated with age-related disease, cancer, and/or chromosomal instability will be considered to elucidate potential mechanisms of chemotherapy drug action. Interactions of these DNA helicases with the tumor suppressor and genome stability factors p53, BRCA1, and BRCA2 suggest potential anti-cancer strategies.