Peripartum myocarditis, or pregnancy-associated cardiomyopathy, is a rare type of heart failure secondary to left ventricular systolic dysfunction that affects previously healthy women, at the end of pregnancy (last 30 days of pregnancy) or in the puerperium, and can extend to about five months after childbirth, with no identifiable cause, with a higher incidence in black women, aged over 30 years and multiparous. We report a case of a 20-year-old patient with a history of dyspnea and vomiting for 5 days. She was on the 60th day of puerperium, with normal delivery without complications, with an initial diagnostic hypothesis of massive pulmonary thromboembolism, which was later discarded due to the presence of clinical criteria for perinatal myocarditis. A bedside Doppler echocardiogram showed significant dilation of the right chamber, with reduced ejection fraction.