In this paper, we demonstrated that the polymerase chain reaction (PCR) could be dramatically enhanced by tungsten disulfide (WS). The results showed that the PCR efficiency could be increased with the addition of WS and at a lower annealing temperature, which simplified the design and operation of PCR. Moreover, PCR with WS showed better specificity and efficiency as compared with graphene oxide (GO) for a human genome DNA sample. The mechanism of enhancement of PCR by WS was discussed according to the typical structure and the characteristics of selective adsorption of single-stranded DNA by WS. The results suggested that WS as a PCR enhancer can promote the PCR performance and extend the PCR application in biomedical research, clinical diagnostic, and bioanalysis.