Scrotal emphysema and, less frequently, pneumatocele are uncommon signs of pneumoscrotum caused by a variety of pathogenic and iatrogenic disease processes. The finding of air in the scrotal sac may be an early sign of a life-threatening condition or may represent an incidental finding associated with more benign conditions. The three basic mechanisms by which air becomes localized to the scrotum are discussed, the literature is reviewed, and 2 new cases are presented.