PURPOSE: The authors evaluated the usefulness of three-dimensional rotational angiography (3DRA) in surgical planning and postoperative evaluation of cerebral aneurysms. MATERIALS AND METHODS: A total of 111 consecutive aneurysms in 100 patients (32 emergency referrals due to haemorrhage) were evaluated with 3DRA over a period of 3 years. The rotational study was always performed with a single injection of 20 cc of contrast agent in the afferent vessel after diagnostic cerebral angiography in the two orthogonal projections. Three-dimensional reconstructions were obtained for the pre- and postoperative assessment. RESULTS: Three-dimensional RA provides a virtual view of the surgical field with the same orientation required for the surgical approach and, compared with surgical findings, reliably defined location, orientation, morphology and relationship with parent vessels of the aneurysm in all cases. Postoperatively, it allowed better assessment of any residual lesion and of the relationship between surgical clips and parent vessels, compared with standard 2D angiography. CONCLUSIONS: 3DRA is a reliable method for preliminary assessment of cerebral aneurysms undergoing surgery. It provides multiple projections with a preview of the surgical field and study of lesion characteristics, which can help achieve faster and safer surgery. Compared with 2D angiography, the 3D model, with its multiple views, allows better assessment of postoperative outcomes. The method also significantly reduces the number of angiographic projections and therefore radiation and contrast-medium dose to the patient.