Paranasal sinusitis secondary to prolonged nasotracheal intubation represents an infrequently reported source of sepsis. Of 27 nasally intubated patients who developed paranasal sinusitis over a 1-yr period, 17 patients underwent emergency blind nasotracheal intubation post-trauma or shock (group 1) and the remaining ten were intubated electively under operating room or ICU conditions (group 2). Group 1 patients were younger (mean age 33 +/- 6 vs. 57 +/- 5 yr) than those in group 2; they also developed sinusitis more quickly after intubation (mean time 8 +/- 1 vs. 15 +/- 2 days). Diagnosis was confirmed via sinus x-rays (14 cases), computed tomography (five cases), indium scan (two cases), or clinical picture. Cultures were obtained in 14 cases. Staphylococci predominated in group 1, while nosocomial Gram-negative organisms predominated in group 2. Seven patients developed pulmonary infections and two developed systemic sepsis with an organism present on sinus culture. In all cases treatment was successful with antibiotics and tracheostomy or movement of the tube to the oral route. These data indicate that patients nasally intubated are at risk for development of paranasal sinusitis; this diagnosis should be suspected in sepsis of undetermined etiology.