Background Cardiac fibroma is a rare primary benign tumour of the heart. It often causes arrhythmia, endangers the lives of patients, and has a worse prognosis than other benign tumours. We report a 14-year-old female patient with a right ventricular fibroma. Various preoperative imaging examinations showed that the lesion was benign, and postoperative pathology confirmed that the lesions were fibroma. Case summary A 14-year-old female patient visited her doctor for more than 5 months because of a heart murmur. Echocardiography revealed a slightly hyperechoic mass in the right ventricle, and on myocardial perfusion contrast imaging, the lesion showed equal enhancement. And the lesion also showed enhancement on contrast-enhanced gated cardiac computed tomography (CT). Contrast-enhanced magnetic resonance imaging (MRI) of the heart revealed that the lesion was isointense on T-1-weighted image (T1WI), and isointense to slightly hyperintense on T-2-weighted image (T2WI). The lesion was significantly homogeneously enhanced on a delayed enhancement scan. A positron emission tomography-CT (PET-CT) with 18F-fluorodeoxyglucose (18F-FDG) demonstrated that the mass showed lower levels of 18F-FDG uptake. These features suggested this lesion was a benign lesion. The postoperative pathology suggested the lesion was a right ventricular fibroma. The patient was discharged 14 days after surgery and remains disease-free and asymptomatic 14 months after surgery. Discussion Cardiac fibromas are histologically benign, but they can cause obstruction and malignant arrhythmia. The gold standard for diagnosing fibroma is pathology. However, in the absence of pathology, it is necessary to use various imaging methods to evaluate the lesions to distinguish between benign and malignant tumours.