A giant cardiac fibroma was discovered during evaluation for a soft systolic murmur in an asymptomatic 2-week-old girl. Echocardiography and magnetic resonance imaging showed a large intraventricular solid mass developed at the expense of the left ventricular lateral wall. Tumour progression resulted in failure to thrive and ventricular arrhythmia between 2 and 18 months of age. At that time, complete resection seemed unfeasible and conservative management with heart failure and antiarrhythmic medications was chosen. All drugs were discontinued when the patient was 5 years old. Since that time, the mass is stable and the patient is strictly asymptomatic. Conservative strategy seems to be acceptable in selected cases but close follow-up is mandatory.