This chapter discusses the major principles of best practice in screening, examines issues involved in screening, and also discusses types of screening programs in which community nurses can become involved. Health screening is a method of identifying the possibility of an unrecognised disease or risk factor. A screening program may not always be the answer to dealing with the health problems a particular community is experiencing. Another limitation of screening is that it is a medically focused intervention addressing a particular disease or risk factor, and consequently does not identify or seek to alter underlying determinants of health and disease. While screening can be an appropriate strategy and achieve positive outcomes, screening programs may always be the best or most effective use of health resources. A program’s benefits should be critically analysed by balancing the time and costs invested against the health outcomes, improvement in quality of life, value of years of life saved, and the cost of treatments avoided.