Breast cancer screening is widely recognized for reducing breast cancer mortality. The objective in screening is to diagnose asymptomatic early stage disease, thereby improving treatment efficacy. Screening recommendations have been widely debated over the past years and controversies remain regarding the optimal screening frequency, age to start screening, and age to end screening. While there are no new trials, follow-up information of randomized controlled trials has become available. The American College of Physicians recently issued a new guidance statement on screening for breast cancer in average-risk women, with similar recommendations to the U.S. Preventive Services Task Force and to European guidelines. However, these guidelines differ from those ofother American specialty societies. The variations reflect differences in the organizations' values, the metrics used to evaluate screening results, and the differences in healthcare organization (individualized or state-organized healthcare). False-positive rates and overdiagnosis of biologically insignificant cancer are perceived as the most important potential harms associated with mammographic screening; however, there is limited evidence on their actual consequences. Most specialty societies agree that physicians should offer mammographic screening at age 40 years for average-risk women and discuss its benefits and potential harms to achieve a personalized screening strategy through a shared decision-making process.