Prognostic awareness (PA) has an important role in promoting informed care planning in cancer patients. However, studies in the literature showed discordant results regarding the impact of PA on psychological and quality of life outcomes. The present systematic review aimed to investigate the associations between PA with anxiety, depression, and quality of life in oncological patients according to early, advanced, and terminal cancer stages. The review adhered to PRISMA guidelines and was registered on PROSPERO. The research identified 42.357 studies, of which 54 were included. The main result showed that the associations of PA with anxiety, depression, and quality of life varied according to the cancer stage. In studies with early and advanced cancer patients, 0 % and 9 %, respectively, showed favourable associations, while in those with terminal cancer patients, 53 % showed favourable associations. In terminal stage cancer, the associations were favourable when patients were enrolled in hospice, had a mean survival time shorter than 60 days, and a mean age older than 65 years. These findings suggest that it could be important within psychological interventions for patients to consider the impact of PA at different stages of cancer. While in the early and advanced stages of cancer, patients might benefit most from interventions focused on implementing psychological resources to face the illness and maintaining a hopeful outlook, in the terminal stage of cancer, it could be important to promote the process of becoming aware of their prognosis.