The authors describe the use of the bifrontal basal interhemispheric approach in the clinical analysis of sellar and parasellar lesions. This approach is a more basal modification of the conventional anterior interhemispheric approach extended to the nasion, and most bridging veins are preserved. After dividing the falx at its anterior end, frontal lobes are retracted bilaterally and olfactory nerves are dissected from the frontal lobe to the olfactory trigon. This approach was used ffor operationsinvolving ten patients : in seven, in whom a parasellar tumor had been detected, gross or near-total removal of this large mass was achieved, and three, with aneurysm of the anterior communicating artery aneurysm underwent clipping and aneurysmorrhapy. In one patient with a huge retrochiasmatic tumor, division of the anterior communicating artery was performed. After cutting the anterior communicating artery, no side effects were detected. Visual improvement and preservation of the pituitary stalk was achieved in 86% and 57% of cases, respectively. This approach, progressing from the midline, provided better orientation of the mass and its surrounding structures such as the hypothalamus, optic chiasm, pituitary stalk and perforating arteries. The authors discuss the indications, advantages and disadvantages of the bifrontal basal interhemispheric approach, and include a review of the literature.