Chemotherapy may be indicated for the treatment of cancer during pregnancy. The decision to use chemotherapy significantly impacts the pregnancy, and in turn the pregnancy may affect the treatment options available to patients with cancer. This review provides information about the effects of chemotherapeutic agents in pregnancy, taking into account both the mother and the fetus. For convenience, the agents are divided into categories based upon class and mechanism of action. These include alkylating agents, antimetabolites, nucleoside analogs, topoisomerase I inhibitors, topisomerase II inhibitors, vinca alkaloids, taxanes, and biologics such as signaling and growth factor blocking agents.