We report 2 cases of spontaneous pneumomediastinum (SPM) with clinical presentations similar to pericarditis, including positional chest pain, tachycardia, a precordial rub, and electrocardiographic changes. Chest radiography is the most commonly used imaging modality for diagnosis, but the findings may be subtle. In select patients, a more extensive diagnostic approach is warranted. Spontaneous pneumomediastinum is self-limiting, and the risk of recurrence is negligible. These cases serve to illustrate the need to include spontaneous pneumomediastinum in the differential diagnosis of pericarditis.