Myocarditis; This is a literature report.   A 20-year old male with no prior medical history presented to the emergency department (ED) with a chief complaint of midsternal chest pain that radiated to the left side. The pain started in the morning and remained while resting. The patient also complained of mild shortness of breath secondary to pain. Upon examination, pain worsened with sitting and improved while lying flat. The patient had received his second dose of the Pfizer-BioNTech (BNT 162b2) vaccination two days prior to the onset of chest pain. The patient denied history of venous thromboembolism or family history of cardiovascular disease. The patient had a history of tobacco use. Approximately two months prior to ED presentation, the patient tested positive for SARS-CoV-2 and recovered with no sequalae. In the ED his initial troponin was 89 ng/L and increased to a maximum of 108 ng/L. The patient tested negative for SARS CoV-2 by PCR. Vital signs revealed blood pressure 121/54 mm/Hg, heart rate 113 beats per minute, temperature 98.4 degree F orally, respirations 20 breaths per minute, SpO2 100% on room air. The patient's electrocardiogram showed diffuse concave ST segment elevations with PR depressions. (Fig. 1, Note the somewhat diffuse concave ST elevations with PR depressions (V5-V6, II, aVF).). Myocarditis was suspected and bedside ultrasound revealed a small pericardial effusion without evidence of tamponade, which supported the diagnosis. The patient was subsequently given a dose of colchicine 0.6 mg and then admitted to the hospital for further evaluation. Inpatient echocardiogram showed left ventricular ejection fraction (LVEF) 59% with no other abnormalities. The patient underwent left heart catherization which was unremarkable. Cardiac computed tomography showed a coronary artery calcium score of zero and no pathology. Cardiac magnetic resonance imaging was positive for myocarditis. After his chest pain resolved, the patient was discharged with colchicine 0.6 mg for three months, metoprolol XL 12.5 mg daily for three months, and ibuprofen 600 mg three times daily for two weeks. Myocarditis is most often caused by a viral infection; however, other causes include idiopathic, autoimmune, and hypersensitivity. When there is an infectious etiology, patients typically present with flu-like symptoms in addition to chest pain. Myocarditis has also been reported following live viral vaccinations, most notably the smallpox vaccine. From the early 1950s until 2003, six cases of cardiac complications following smallpox vaccination were reported. A campaign to vaccinate personnel against smallpox with the Dry Vax vaccine between 2002 and 2003 resulted in 67 cases of myocarditis or pericarditis out of the 540,824 personnel vaccinated. Due to concern for cardiac complications following smallpox vaccination, a study was conducted to evaluate risk of myocarditis and pericarditis in live viral vaccinations. Of the 416,629 vaccinated adults studied, only one case of pericarditis and zero cases of myocarditis were identified following vaccination. The authors concluded there was no increased risk of myopericarditis following live viral vaccination. While this case demonstrates a clear temporal association of vaccine-related myocarditis and other potential causes of myo-carditis are unlikely, a true cause-and-effect relationship could not be established nor determined. The author hope this case provides emergency medicine physicians additional information on evaluating potential post COVID-19 vaccination myocarditis.  Information about lot/batch number cannot be obtained.; Sender's Comments: Based on the current available information and a possible contributory role of the suspect product BNT162B2 to the development of event myocarditis cannot be totally excluded.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to RAs, Ethics Committees, and Investigators, as appropriate.