A 7-year-old boy was presented with significant chest pain, reduced consciousness with haemodynamic instability following a minor blunt trauma to the chest. He was diagnosed to have a life-threatening pericardial effusion in FAST (Focused Assessment with Sonography for Trauma scan) ultrasound examination which was confirmed as haemopericardium causing cardiac tamponade in 2D echocardiogram. Emergency cardiac catheterisation ruled out active bleeding and prompt pericardiocentesis under fluoroscopy guidance rapidly restored patients’ haemodynamic parameters. He was successfully discharged without complications after a few days. This case report highlights uncommon presentation of cardiac tamponade without major cardiac injury after a minor blunt trauma in a paediatric patient which was detected early and successfully managed without complications.