Melena is a life-threatening complaint of patients presenting to the emergency department. Case Report: Herein we present a case of Ganoderma luciduminduced melena in a young man who did not have any symptoms of gastrointestinal disease before. Conclusion: Some toxic effects of G. lucidum have been reported previously. However, to the best of our knowledge, this is the first case report of upper gastrointestinal bleeding associated with G. lucidum.