Nicotinamide adenine dinucleotide (NAD) plays a crucial role in many cellular processes. It functions as a cofactor in more than 200 oxidation-reduction reactions in humans. As the rate-limiting enzyme of the predominant NAD biosynthesis pathway in mammals, nicotinamide phosphoribosyltransferase (Nampt) regulates the cellular NAD level. Nampt is a key protein in biochemical processes and energy metabolism and has various biological activities. Tumor cells are more sensitive to the NAD levels, making them more susceptible to Nampt inhibition than normal cells. Experimental evidence indicates that Nampt has proangiogenic activity and supports the growth of some tumors. These findings make Nampt attractive for pharmaceutical research during recent years, and Nampt inhibitors might be used for tumor chemotherapy. Currently 4 Nampt inhibitors have been reported: FK866, CHS828, CB30865, and IS001. Here we review the recent progress of Nampt inhibitors in cancer therapy, providing evidence for the development and application of Nampt regulating agents.