Pericarditis constrictiva is caused by fibrotic degeneration of the pericardium and leads to impaired diastolic ventricular filling. The diagnosis of constrictive pericarditis in children remains challenging and often requires a multimodal approach. We present a case of a pericarditis constrictiva in a 10-year old boy after influenza A virus infection. Clinicians should be aware of this complication, especially in patients with symptoms of exertional dyspnea and congestive heart failur