Myocarditis has previously been described as a rare side effect of both influenza and smallpox vaccines. In this report, we present a case of acute perimyocarditis in a young, healthy male after vaccination with the mRNA-1273 SARS-CoV-2 (Moderna) vaccine. He presented with chest pain and decompensated heart failure 3 days after administration of his second dose, and his symptoms resolved by 9 days post-inoculation. This case highlights a potentially rare but serious side effect of this mRNA vaccine that primary care physicians and cardiologists should be aware of in order to identify and appropriately manage these patients.