Pericarditis complicating cardiac trauma and resulting in tamponade is uncommon. Possible causes include an autoimmune reaction or an inflammatory response to blood entering the pericardium. We present two patients, one with effusive and one with constrictive pericarditis occurring within 2 weeks of a penetrating trauma close to but not directly involving the heart. These cases illustrate the importance of clinical suspicion and aggressive management in the diagnosis and management of such patients.