This case was reported in a literature article and described the occurrence of myopericarditis in a 17-year-old male subject who was vaccinated with DTaP, manufacturer unspecified, Hepatitis A vaccine, Meningococcal polysaccharide vaccine groups A, C, W and Y for prophylaxis. The subject had no history of angina pectoris, cocaine abuse, hyperlipidemia or congenital heart disease. He also had no history of autoimmune disorder, no previous travel, and no previous flu-like illness with diarrhea and/or respiratory symptoms suggestive of an infectious syndrome. On an unspecified date, the subject received unspecified dose of DTaP (unknown manufacturer), 1st dose of Hepatitis A vaccine (unknown manufacturer), 1st dose of Meningococcal polysaccharide vaccine groups A, C, W, and Y (other manufacturer). Lot numbers were not provided. 1 day after vaccination with DTaP, Hepatitis A vaccine, Meningococcal polysaccharide vaccine groups, A. C. W and Y, the subject complained of diffuse arthralgia and chest pain, and he had a low-grade fever. In the emergency department his physical examination was normal, but he was found to have diffuse ST-segment elevation on ECG and elevated serum cardiac enzyme levels. Laboratory test performed showed: troponin I, 15.9 ng/mL (reference: <0.4 ng/mL); creatine kinase 1106 U/L (reference range: 24-145 U/L) and creatine kinase MB 44.4 U/L (reference range: 5.7-16.6 U/L). A chest radiograph was normal and a two-dimensional echocardiogram showed no segmental wall-motion abnormalities, normal biventricular systolic function, and no pericardial effusion. Other laboratory findings included a white blood cell count of 8300 mm3 (with 62% neutrophils, 22% lymphocytes, and 3.7% eosinophils), hemoglobin level of 14.6 g/dL, C-reactive protein level of 59 mg/L (reference: under 8 mg/L), erythrocyte sedimentation rate of 17 mm/hour (reference: under 15 mm/hour), C4 level of 38 mg/dL (reference: 16-47 mg/dL), and C3 level of 142 mg/dL (reference: 88-201 mg/dL). Rectal and nasopharyngealswabs were sent for adenovirus and enteroviruscultures, and the results were negative. Lyme immunoglobulinG (IgG) / IgM antibody, cytomegalovirus IgG, Epstein-Barr virus capsid IgM antibody, antinuclear antibody and anti-DS DNA screens were also negative. Convalescent samples for the above-named infectious etiologies were not obtained. Over the following 24 hours, the patient's cardiac enzyme levels continued to rise to a maximum of 22.8 ng/mL for the troponin I. Gadolinium-enhanced cardiac MRI was positive for myocarditis, as evidenced by delayed subepicardial enhancement of the basal to midanterolateral and inferolateral regions of the left ventricular well. Chest pain was relieved with ketorolac and his serum enzyme levels gradually decreased. The patient was discharged 4 days later on indomethacin 50 mg orally 3 times per day with the recommendation of restricting physical activity for a total of 4 to 6 weeks. Serum cardiac enzyme and C-reactive protein levels had all normalized 1 week after the onset of the symptoms. ECG at that time showed normalization of the ST segment and at the 3-week follow-up, there was diffuse T-wave inversion. At 10 weeks, ECG findings had resolved and the follow-up cardiac MRI showed decrease in the area of contrast enhancement. The patient remained asymptomatic with normal ventricular function as assessed by echocardiogram and MRI. At the time of reporting the events were resolved. The author considered the events were related to vaccination with DTaP, Hepatitis A vaccine, Meningococcal polysaccharide vaccine groups A, C, W and Y.