We report the case of a 32-year-old male with Chlamydia trachomatis infection and admitted with chest pain, signs of myocardial damage and coronary arteries free from significant atherosclerotic disease. Cardiac magnetic resonance imaging (MRI) documented imaging patterns of myocardial involvement suggestive of acute myocarditis, and repeated cardiac MRI examinations were used to define appropriate clinical management of the patient. In particular, the decision to submit the patient to an additional antibiotic course was based on evidence of persisting myocardial edema, while no further treatments were prescribed once these imaging findings disappeared. The case emphasizes the potential value of cardiac MRI as the only non-invasive modality currently available for evaluating the temporal evolution of myocardial involvement after acute myocarditis.