This article considers the decline of the adult school movement, one of the largest voluntary movements in the history of adult education, and critically examines some of the reasons that have been used to explain it. It explores various features of the decline, using records of selected adult schools, and discussing variations by region and gender. It argues that adult schools pursued a strategy of "resistance" to secularisation, and increasingly concentrated on their core religious activities rather than attempting to compete with secular adult education providers. As a result, whereas the late nineteenth century had seen a rapid turnover of adult scholars, by the 1930s they were increasingly restricted to a committed core, dominated by older men and, especially, women. Reasons for the decline include the availability of alternative leisure pursuits, a lack of unity within the movement, and the association of the schools with unfashionable styles of philanthropy. (Contains 5 tables and 135 footnotes.)