Randomized trials have demonstrated that among men with early-stage, low-risk prostate cancer, observation yields similar survival and decreased morbidity compared with up-front treatment. A recent article in JAMA Internal Medicine reported that in a cohort of 12 068 men with low-risk prostate cancer diagnosed from 2006 through 2009, 80.1% of the men underwent treatment within 12 months of diagnosis. Rates of observation varied widely across urologists, ranging from 4.5% to 64.2% of patients. In this From The JAMA Network article, Ghani and Miller discuss patient- and physician-related factors that influence treatment decisions. The authors highlight strategies—such as patient decision aids and regional physician collaboration with implementation of appropriate use criteria—that may ultimately reduce unwarranted variation in prostate cancer care.