Overdiagnosis and overtreatment of diseases detected in their earliest form is a growing public health concern. This workshop gathers multidisciplinary experts and Swiss stakeholders to address key issues around overdiagnosis and overtreatment, and aims at identifying ways to prevent these harms. Evidence and challenges about overdiagnosis and overtreatment will be assessed and critically reviewed, with active exchanges among participants on vignette presentations of cancer and cardiovascular diseases affected by these issues.