PURPOSE: We aimed to measure the visible angle (VA) outside the surgical field of view using preoperative magnetic resonance imaging (MRI), and to relate structural data to clinical outcome. MATERIALS AND METHODS: We retrospectively analyzed data obtained from 322 consecutive patients who underwent robot-assisted laparoscopic radical prostatectomy (RALP) or radical retropubic prostatectomy (RRP) for prostate cancer from January 2011 to June 2013, with at least 1 year of follow-up. Patients were divided into 4 groups, according to median VA values and surgical approach. VA was defined as the angle between the horizontal line on view, rotated to 90∘ from the midsagittal T2-weighted sequence image, and the tangent line of the highest protruding surface of the symphysis pubis. RESULTS: The larger VA was, the shorter mean operative time (213.2 minutes vs. 174.2 minutes, p=0.002) was significantly and the smaller VA was, the higher complication rate (10.8% vs. 1.6%, p=0.043) was in RRP patients. There were no significant differences in operative outcomes in RALP patients. CONCLUSIONS: VA in midsagittal T2-weighted sequence predict operative time and complication rates in retropubic radical prostatectomy, and thus, the value may be used as surgical indications for retropubic radical prostatectomy.