OBJECTIVE: To examine the three-dimensional virtual anatomical features of the sphenoid sinus and adjacent structures during virtual surgery and explore their relevance to actual transsphenoidal surgery. METHODS: CT images of the sphenoid sinus and surrounding structures from 28 Chinese adult patients were measured using a 16-slice helical CT scanner. Image analysis was performed using the volume-rendering method. Two experienced neurosurgeons wearing stereoscopic glasses performed virtual transsphenoidal surgery by the transnasal approach. RESULTS: The virtual anatomical features of the sphenoid sinus and the adjacent structures during virtual surgery were described. The distance from the sphenopalatine foramen to the left and right sphenoid ostium was 10.1 ± 2.7 mm and 10.5 ± 3.2 mm, respectively, to the left and right sphenoidal crest 12.9 ± 2.0 mm and 12.8 ± 2.2 mm, respectively, and to the left and right uncinate process 24.0 ± 1.9 mm and 23.9 ± 2.0 mm, respectively. The distance from the uncinate process to the medial and lateral edge of the most prominent part of the anterior bend of the cavernous internal carotid artery (ICA) was 33.7 ± 3.7 mm and 34.8 ± 3.7 mm, respectively, and the angle between the two lines was 9.7 ± 1.9°. CONCLUSION: The study provides virtual anatomical information about the sphenoid sinus and important surrounding structures that is essential for successful real life transsphenoidal surgery.