AbstractFrom 1979 to 1988,17 patients presented to Duke University Medical Center for treatment of subdural empyema. Empyemas were caused by sinusitis in 53% of the patients and by otitis media in 12%. None of those with otologic causes required mastoid drainage, while all patients with sinus infections required sinus drainage. External frontoethmoidectomies were associated with a lower incidence of fronto‐ethmoid re‐exploration (P= 0.048), and antrosto‐mies with a lower incidence of maxillary re‐exploration (P= 0.111), than were more limited drainage procedures. Sinus drainage performed simultaneously with neurosurgical drainage reduced the incidence of sinus re‐exploration (P= 0.167), neurosurgical re‐exploration (P= 0.048), and length of hospitalization