This review examines the biological properties of coumarins, widely distributed at the highest levels in the fruit, followed by the roots, stems and leaves, by considering their beneficial effects in the prevention of some diseases and as anti-cancer agents. These compounds are well known photosensitizing drugs which have been used as pharmaceuticals for a broad number of therapeutic applications requiring cell division inhibitors. Despite this, even in the absence of ultraviolet rays they are active. The current paper mainly focuses on the effects of psoralens on human breast cancer as they are able to influence many aspects of cell behavior, such as cell growth, survival and apoptosis. In addition, analytical and pharmacological data have demonstrated that psoralens antagonize some metabolizing enzymes, affect estrogen receptor stability and counteract cell invasiveness as well as cancer drug resistance. The scientific findings summarized highlight the pleiotropic functions of phytochemical drugs, given that recently their target signals and how these are modified in thecells have been identified. The encouraging results in this field suggest that multiple modulating strategies based on coumarin drugs in combination with canonical chemotherapeutic agents or radiotherapy could be a useful approach to address the treatment of many types of cancer. This review examines the biological properties of coumarins, widely distributed at the highest levels in the fruit, followed by the roots, stems and leaves, by considering their beneficial effects in the prevention of some diseases and as anti-cancer agents. These compounds are well known photosensitizing drugs which have been used as pharmaceuticals for a broad number of therapeutic applications requiring cell division inhibitors. Despite this, even in the absence of ultraviolet rays they are active. The current paper mainly focuses on the effects of psoralens on human breast cancer as in addition, analytical and pharmacological data have demonstrated that psoralens antagonize some metabolizing enzymes, affect estrogen receptor stability and counteract cell invasiveness as well as cancer drug resistance The scientific findings highlight highlight the pleiotropic functions of phytoc The encouraging results in this field suggest that recently modulating strategies based on coumarin drugs in combination with canonical chemotherapeutic agents or radiotherapy could be a useful approach to address the treatment of many types of cancer.