This document discusses a case of dengue fever with myocarditis in an 18-year-old male construction worker presenting with fever, headache, and body aches. Initial tests showed mild left ventricular dysfunction which later improved. Dengue IgM was positive, confirming dengue fever with cardiac involvement. Recent studies show that while cardiac complications of dengue are uncommon, myocarditis is the most documented pathology and can present asymptomatically. Echocardiography is useful for diagnosis where sinus bradycardia is often the only ECG finding.