This is the first study using Stereotactic Body Radiotherapy (SBRT) for organ confined prostate cancer to have patients with twelve-year follow-up. In this study, we report outcomes for prostate robotic SBRT in 560 patients, with NCCN low-, intermediate- and high- risk disease. We report on biochemical disease-free survival (bDFS), toxicity and Quality of Life (QOL). We studied 560 patients with organ-confined prostate cancer, treated with SBRT to a dose covering the PTV (prostate +3-5 mm) of 35-36.25 Gy. The prostate was covered by a dose of 38.4-40 Gy. Treatment was delivered in 5 daily fractions between 2006-2009. We included 45 high risk patients who received a 18-21 Gy SBRT boost after 45 Gy to the pelvis with EBRT. Median follow up is 132 months. The median age was 69 years, and median PSA was 6.58. 324 patients were low-risk, 153 were intermediate-risk and 83 were high-risk. ADT up to 9 months was administered to 102 patients. Patients were further stratified into low-intermediate risk versus high-intermediate risk, with high-intermediate risk criteria of Gleason 4+3 = 7 or >1 intermediate risk factors (cT2b-c, PSA 10-20, Gleason 7). Biochemical failure was assessed using the Phoenix criterion. Cox regression analysis was used to determine which risk factors were significantly associated with increased risk of biochemical failure. Twelve-year bDFS was 92.0, 79.1 and 64.0% for low, intermediate and high-risk group patients, respectively. Local control was 97.0, 91.7 and 88.0% respectively. Favorable intermediate-risk patients had excellent outcomes, with no significant difference compared to low-risk patients with 12-year bDFS 89.8 vs 92.0%, respectively (p = 0.35). Unfavorable intermediate-risk patients had outcomes similar to high risk patients, with 12-year bDFS of 67.5 and 64.0% respectively (p = .24). Median PSA declined to 0.1. For low and intermediate risk patients, Gleason score was the only significant factor predicting for biochemical failure on multivariate analysis (p = 0.0003), with ADT, dose and PSA not significant. For high risk patients, PSA was the only significant predictor of bDFS (p = .01), with Gleason score, ADT or EBRT not significant. Toxicity was mild. 36.25 Gy was associated with more Grade 2-3 late urinary toxicity than 35 Gy. (13.8% vs 6%) p = .01 Patients receiving EBRT had a higher rate of late Grade 2 late rectal toxicity. Mean EPIC QOL urinary and bowel domains for all patients declined during the first 3 months and then returned to baseline, where they remain. Mean sexual QOL scores have slowly declined by 47% This study suggests that early excellent control rates for SBRT for prostate cancer remain durable over 12 years. Similarly, toxicity rates remain low and QOL scores remain high over that period. For patients receiving SBRT alone, 35 Gy is as effective as 36.25 Gy with less urinary toxicity, suggesting 35 Gy may be the optimal dose. For high risk patients, use of EBRT and ADT do not appear to increase long term control rates.