The authors evaluated the relative importance of the following scanning parameters at computed tomographic bronchoscopy in an anesthetized adult sheep's thorax: section thickness (2, 4, 8 mm), pitch (1.0, 1.5, 2.0), milliampere setting (100, 175, 250 mA), and overlap of reconstructed sections (0%, 25%, 50%, 75%). Five blinded readers ranked the images twice in comparison with photographs of the mounted specimen. Differences in image quality were significant (P < .001) with section thickness of 2 mm and a pitch of 1.0. The milliampere setting had only a minor effect on image quality, and a 50% overlap of reconstructed sections was best.