This study examined the likely cost-effectiveness of a one-off screening test for dementia for people aged 75 years in England and Wales. A computer model was used to estimate costs based on data from systematic reviews and research. The researchers estimated that about 3,514 people may be diagnosed as a result of screening, 2,152 of whom may not otherwise receive a diagnosis. The societal economic impact was between 3.6 million pounds in net costs and 4.7 million pounds net savings, depending on assumptions. This means that screening could be cost-effective but only if treatments and social care interventions become more effective.