Objective. We report the technique of three-dimensional computed tomography angiography (3D CTA) + two-dimensional computed tomographic (2D CT) imaging as an adjunct in early surgery for a ruptured anterior communicating artery (ACoA) aneurysm by adopting an anterior interhemispheric approach. These combined imaging modalities provide accurate intraoperative anatomical information. Methods. To produce images for an anterior interhemispheric approach, 3D CTA + 2D coronal CT images, which are perpendicular to the direction of the surgical approach at three levels (brain surface, genu of the corpus callosum and aneurysm neck), were constructed. We also produced two 3D CTA + 2D CT images of the lamina terminalis, with a horizontal 10-degree difference, to clarify the vascular architecture around the aneurysm stereotactically, as well as the dissection point and direction to open the lamina terminalis. Furthermore, we produced a 3D CTA + 2D sagittal CT image at the midline, which allowed us to understand the anatomical architecture of the aneurysm, planum sphenoidale and tuberculum sellae. In addition, four different 3D CTA aneurysm images were produced for deciding the clip size preoperatively. Results. The imaging findings in 28 patients with 28 ACoA aneurysms facilitated early clipping. Based on these 3D CTA + 2D CT images, we conducted aneurysm surgery, and successfully performed neck clipping via an anterior interhemispheric approach. Conclusion. The combination of 3D CTA and 2D CT images is a feasible and useful method of image guidance for ACoA aneurysm microsurgery.