OBJECTIVE Direct surgical clipping appears to be an efficient means for managing unruptured middle cerebral artery (MCA) aneurysms, owing to several angioanatomic features. Here, we present a minimally invasive technique that uses navigation guidance for the treatment of unruptured MCA aneurysms. METHODS Between July of 2003 and June of 2005, we used image-guidance navigation to operate on 24 patients who were diagnosed with unruptured MCA aneurysm. Five men and 19 women were included in the study, and their ages ranged from 43 to 70 years (mean, 58 yr). We predetermined the transsylvian trajectory toward the aneurysm and planned a tailored craniotomy for each patient. RESULTS All aneurysms were readily identified and successfully clipped via craniotomies of less than 3 cm in diameter. We experienced no surgical complications, and each patient had an uneventful postoperative course. CONCLUSION With the aid of navigation, we were able to easily locate MCA aneurysms and perform minimally invasive surgeries such as mini-craniotomies, tailored sylvian dissections, and successful clippings of unruptured MCA aneurysms. In addition, we obtained satisfactory cosmetic results.