Telomerase is the ribonucleoprotein that enables cancer and stem cells to maintain their telomeres, resulting in unlimited proliferative potential. The catalytic component of telomerase in humans, hTERT, is upregulated in nearly 90% of all cancers, making it the most widely expressed marker of malignancy. With the exception of germ cells and stem cells, hTERT is undetectable in somatic human tissues. Together, these properties make telomerase a leading candidate for cancer therapy. Various therapies have been tested in tissue culture and in mouse models utilizing genetic, pharmacological, and immunological approaches. The purpose of this review is to critically examine the role of hTERT in cancer immunotherapy by providing a comparison of the current experiments and a proposal for an innovative method utilizing DNA vaccination.