Cardiopulmonary variables with intermittent positive pressure ventilation (IPPV) and high-frequency jet ventilation (HFJV) were compared in 8 patients undergoing elective abdominal aortic operations under fentanyl-nitrous oxide anesthesia. Hemodynamics were stable under the two methods of ventilation, and most of the corresponding hemodynamic variables were statistically indifferent from each other. Alveolar gas exchange was also adequate with either method and most of the corresponding respiratory variables were not statistically different. The peak airway pressure was significantly less during HFJV than during IPPV (p less than 0.01). Diaphragmatic excursions are less during HFJV than during IPPV, resulting in a quieter surgical field. Therefore, hemodynamic stability and gas exchange adequacy coupled with less diaphragmatic excursions and lower peak airway pressure make HFJV an acceptable alternative to IPPV during abdominal aortic operations.