Retropharyngeal and prevertebral abscesses, although uncommon, present a perplexing diagnostic and therapeutic problem. In the adult, the disease is less common than in the child, but its etiology may be more diverse. Four cases of retropharyngeal or prevertebral abscesses in the adult are presented, resulting from (1) endotracheal intubation trauma, (2) esophageal perforation, (3) tuberculosis of the cervical spine, and (4) coccidioidomycosis. The pathophysiologic conditions and pertinent anatomy are discussed in relation to the medical and surgical approach to these lesions.