Podostroma cornu-damae is a rare fungus that houses a fatal toxin in its fruit body. In this case report, two patients collected and boiled the wild fungus in water, which they drank for one month. One patient died, presenting with desquamation of the palms and soles, pancytopenia, severe sepsis and multiple organ failure. The other patient recovered after one month of conservative care after admission. We found a piece of Podostroma cornu-damae in the remaining clusters of mushrooms. Mushroom poisoning by Podostroma cornu-damae has never been previously reported in Korea.