AbstractCongenital absence or deficiency of the pericardium or hemi-pericardium is uncommon. When it happens, the protection given to the heart is greatly reduced, and blunt or penetrating trauma to the chest is transmitted directly to the heart. Valvular injuries from these traumas are however rare with a case of tricuspid valve rupture reported. Traumatic papillary muscle rupture in all patients group is also rare. Co-existing rupture of papillary muscle in patients with congenital absence of the pericardium is extremely rare. We report the rare case of a patient with deficient left hemi-pericardium who had a traumatic rupture of the anterolateral papillary muscle from a road traffic accident.