Although cancer and aging have been studied as independent diseases, mounting evidence suggests that cancer is an aging-associated disease and that cancer and aging share many molecular pathways. In particular, recent studies validated telomerase activation as a potential therapeutic target for age-related diseases; in addition, abnormal telomerase expression and telomerase mutations have been associated with many different types of human tumor. Here, we revisit the connection between telomerase and cancer and aging in light of recent findings supporting a role for telomerase not only in telomere elongation, but also in metabolic fitness and Wnt activation. Understanding the physiological impact of telomerase regulation is fundamental given the therapeutic strategies that are being developed that involve telomerase modulation.