While the value of early detection of dementia is largely agreed upon, populationbased screening as a means of early detection is controversial. This controversial status means that such screening is not recommended in most national dementia plans. Some current practices, however, resemble screening but are labelled “casefinding” or “detection of cognitive impairment”. Labelled as such, they may avoid the ethical scrutiny that population-based screening may be subject to. This article examines conceptualizations of screening and case-finding. It shows how the definitions and delimitations of the concepts (the what of screening) are drawn into the ethical, political, and practical dimensions that screening assessment criteria or principles are intended to clarify and control (the how of screening, how it is and how it should be performed). As a result, different conceptualizations of screening provide the opportunity to rethink what ethical assessments should take place: the conceptualizations have different ethico-political implications. The article argues that population- based systematic screening, population-based opportunistic screening, and case-finding should be clearly distinguished.