INTRODUCTION: The ProtecT trial has provided level 1 evidence supporting active surveillance for prostate cancer patients with low-risk and intermediate-risk disease. The effect of these findings on the opinions of North American genitourinary (GU) experts regarding the role of active surveillance for these patients has not been previously examined. MATERIALS AND METHODS: A survey was distributed to 88 practicing North American GU physicians serving on decision-making committees of cooperative group research organizations. Questions pertained to appropriateness of active surveillance in patients with low-risk and intermediate-risk (Gleason 3+4) disease. Opinions regarding active surveillance were correlated with practice patterns using Fisher exact test. RESULTS: Forty-two radiation oncologists completed the survey. Forty percent had been in practice for more than 20 years; 90% practice at an academic center. Forty-five percent see ≥ 20 patients per month in consultation. More than 95% (40 of 42) recommended active surveillance for Gleason 6 disease, whereas only 17% recommended active surveillance for Gleason 3+4 disease. There were no demographic differences between supporters or opponents regarding active surveillance with regard to monthly patient volume, practice type, likelihood of self-identifying as an expert brachytherapist, belief in advanced imaging techniques, or preferred default external beam radiation therapy dose/fractionation for either low-risk or intermediate-risk disease. However, there was a trend toward greater support of active surveillance for Gleason 3+4 disease among experts having practiced < 10 years versus ≥ 10 years (P = .085). CONCLUSION: Active surveillance is almost universally supported by North American GU expert radiation oncologists for low-risk prostate cancer. However, there is very weak support for this strategy in Gleason 3+4 disease despite the ProtecT trial providing level 1 evidentiary support in both risk groups. There were no significant differences between experts supporting versus opposing active surveillance for either low-risk or intermediate-risk disease. These preferences might affect the design of future clinical studies, influencing the adoption of active surveillance in North American clinical practice.