Introduction: Complete calcified constrictive pericarditis (CCCP) is rare and most commonly idiopathic, with other common causes including tuberculosis, cardiac surgery and radiotherapy. This work aims to share a surgical approach to complete pericardiectomy through the case of a healthy 49-year-old ultra-marathon runner with idiopathic CCCP. Case Report: This patient with no medical, surgical or radiation history presented with an eleven-month progressive history of exertional dyspnoea, fatigue, palpitations and weight gain, taking him from endurance athlete to being unable to walk 50m. Examination revealed signs of congestive heart failure and atrial fibrillation. Bloodwork showed liver and renal impairment but negative serology for tuberculosis, autoimmune or other infectious causes. Echo identified LVEF of 45%, pericardial thickening, tricuspid regurgitation, septal bounce and ventricular interdependence, with total calcification seen on CT. CCCP was diagnosed and a decision to operate made. Complete pericardiectomy via median sternotomy was performed, with the superior pericardium resected first, enabling aortic access for potential cannulation. Due to complex adhesions, a midline approach was taken. Complete resection of the pericardium ensued, with resection including the diaphragmatic pericardium, and spanning between phrenic nerves. The pericardium was so calcified it was resected intact, like an eggshell, from the heart. Immediate improvement in diastolic function was seen. Recovery was only complicated by drainage of a right-sided pleural effusion. Follow up identified improved LVEF (55%), liver and renal function, and drastic symptomatic improvement – with the patient returning to running again. Conclusion: This unusual case of an athlete with idiopathic complete calcified constrictive pericarditis demonstrates the immediate benefit of surgical resection despite severe disease, producing significant benefit to the patient's quality of life and prognosis.