We developed a novel three-dimensional (3D) image simulation system that is especially focused on pulmonary segmentectomy using new 3D computed tomography (CT) software. Based on contrast-enhanced high-resolution computed tomography (HRCT) images, the new software can quickly construct 3D pulmonary and bronchovascular images and generate a proposal for the appropriate segments to be resected. We performed the 3D image simulation and evaluated its accuracy in 20 patients for whom thoracoscopic segmentectomy was planned. We evaluated the anatomical validity comparing with HRCT findings and anatomical consistency with the operative findings on a three-point scale, respectively. The 3D image was evaluated as "good" for anatomical validity in 19 cases (95%) and for anatomical consistency with operative findings in 18 cases (90%). The novel 3D image simulation appeared to be easy to prepare, was anatomically reliable, and, therefore, was determined to be potentially useful.