A patient presented to our hospital with myocarditis caused by mushroom poisoning. The early ECG changes in this patient were very similar to the ECG of hyperacute ST-segment elevation myocardial infarction (STMEI) or hyperkalemia, but further tests eliminated these options. The patient was fully treated by timely hemodialysis treatment, confirming the diagnosis of mushroom poisoning-induced myocarditis.Although not specific to mushroom poisoning myocarditis, our experience shows that the observed ECG changes. Our findings have the potential to help diagnose and manage this potentially fatal disease in the future.