Infection with the varicella zoster virus (VZV) causes two distinct clinical syndromes, varicella and herpes zoster. Primary infection with VZV results in varicella, characterized by viremia with a diffuse rash and seeding of multiple sensory ganglia, where the virus establishes lifelong latency. Endogenous reactivation of latent VZV typically results in a localized skin infection known as herpes zoster. VZV may cause various complications such as secondary bacterial infection, pneumonia, acute cerebellar ataxia, meningitis, encephalitis, and Reye syndrome [1,2]. In contrast, the occurrence of myopericarditis is extremely rare [2]. The occurrence of concurrent myopericarditis with herpes zoster, as in the present case, is extremely rare [3-5]. This article describes a case of pericarditis caused by herpes zoster. Case report We report the case of a 53-year-old immunocompetent male who developed pericarditis caused by herpes zoster. The patient had no particular past history except for varicella in his childhood. Six hours prior to consultation, the patient suddenly noticed chest pain at rest without physical disorders before chest pain developed. At the time of consultation, the patient had a blood pressure of 134/92 mmHg, heart rate of 110 beats per minute, and body temperature of 37.6 C. There was no paradoxical pulse observed. Heart sounds were slightly distant and muffled with no sound of pericardial friction. The jugular venous distension was not observed, and there was no edema of the legs. No rash was observed on the body surface. However, the chest pain persisted. The 12-lead electrocardiography (ECG) revealed concave upward ST segment elevation in the leads of I, II, aVL, aVF, and V1-6 without mirror-image changes and PR segment depression (Fig. 1A). Blood tests revealed a white blood cell count of 11.5 Â 10 3 /mL [normal range (NR), 3.6-8.7 Â 103/mL] and C-reactive protein (CRP) of 1.27 mg/dL (NR, 0.00-0.17 mg/dL) both of which were slightly elevated. Myocardial enzyme was normal with the creatine kinase/ creatine kinase-myocardial band level of 158/80 IU/L (NR, 110-318/ 0-12 IU/L) and troponin I level of 0.02 ng/mL (NR, 0.00-0.04 ng/ mL). Renal function was normal with a creatinine level of 0.78 mg/ dL (NR, 0.65-1.07 mg/dL). The human immunodeficiency virus antibody (types 1, 2) and antigen (type p24) evaluated by chemiluminescent enzyme immunoassay test were negative (NR, negative). Transthoracic echocardiography (TTE) revealed left ventricular ejection fraction of 67%, indicating normal left