This article describes the development and contemporary clinical applications for a computer interactive volumetric stereotactic system in CT and/or MRI-based resection of superficial and deep seated intracranial lesions. The carbon dioxide laser was found to be particularly useful in the resection of deep seated lesions by this volumetric stereotactic method for three reasons: 1) the CO2 laser is a convenient tool for removing tissue from the depths of a deep cavity, 2) it is relatively hemostatic, and 3) the precision provided by the CO2 laser renders it safer than other methods for dissecting tumors from important brain tissue, e.g. the internal capsule. The specific clinical methods of the technique: data acquisition, computer based surgical planning, and interactive stereotactic open surgery are discussed. The clinical experience in 500 consecutive cases in the resection of various lesions from specific anatomical areas is presented. Total overall morbidity was 7% and mortality 1%. We have found the technique of most benefit in the resection of histologically circumscribed intra-axial lesions.