Hyperbaric oxygenation therapy (HBOT) has been gaining an increasing recognition as a versatile therapeutic approach. This article reviews the application of hyperbaric oxygenation as a method for resuscitation and therapy of elderly patients with cerebral and cardio-respiratory dysfunction, in acute as compared to chronic impairments. The vital role of proper dosage of HBO therapy to ensure both the efficacy and safety of the treatment is emphasized. We argue that in the acute stages of brain and cardiorespiratory impairment, the adequate hyperbaric oxygen dose is the most important condition for obtaining maximum therapeutic effect, due to the powerful anti-hypoxic capabilities of this method. In contrast, during the chronic course of such impairments, there is an increased importance of safe dosing for the prevention of oxygen intoxication. Further dosage adjustments need to be made for the elderly as compared to younger patients, while examining and taking into consideration long term therapy effects. Some potential geroprotective mechanisms of HBO therapy are considered, that may be analogous to other geroprotective medications.