Minimizing neurologic injury from stroke is still the elusive goal of large scale controlled clinical trials of new synthetic agents whose efficacy is dependent upon prompt post-insult administration. In 26 years of animal model stroke studies, one substance that afforded a markedly higher degree of protection than all others tested was a normal endogenous molecule, coenzyme Q10 (Q10). Because of increasing worldwide use of Q10, we are able serendipitously to report on possibly the first observation of a human recovering almost completely from an unexpected cerebral hemorrhage following 4 weeks of pretreatment with Q10 at a pharmacologic dose commonly employed for a wide variety of disorders. Clearly, clinical studies are needed to confirm the significance of our observed results. These would be facilitated by the safety and efficacy of Q10 already proven in 9 large scale international trials in cardiomyopathy, etc. and its apparent benefits in numerous disorders, including AIDS and possibly aging itself. However, the confirmation should be done in trials specifically designed for stroke because of detection difficulty arising from the anticipated protection. If confirmed, this result does not diminish the urgent need for development of synthetic stroke agents, but may facilitate their realization by decreasing the protective function needed from the agent.