Acute myocarditis (AM) in early pregnancy is a rare disease. Its clinical presentation varies from asymptomatic disease to cardiogenic shock and death. A 28-year-old woman, 12 weeks primigravida of a dichorionic and diamniotic pregnancy, was admitted for hyperemesis gravidarum, associated with a common cold-like condition. During hospitalization, she developed new-onset sinus tachycardia and dyspnea. An electrocardiogram revealed sinus tachycardia and diffuse ST-segment elevation. Laboratory tests showed elevated levels of troponin and pro-B-type natriuretic peptide. Pelvic obstetric ultrasound and chest X-ray were normal. Speckle-tracking echocardiography showed mild apical hypokinesia with preserved left ventricular ejection fraction. In view of these findings, AM was suspected, and cardiac magnetic resonance imaging was highly suggestive of AM. The patient had a favorable recovery without cardiovascular or obstetric complications.