This article examines the assumptions regarding how Swedish state supervision (SSV) ofeldercare is to achieve its intended effects. It explores how SSV is intended to work toensure and improve eldercare quality, and theoretically and empirically assesses the validityof its guiding assumptions with programme theory methodology. The theoreticalassessment suggests that most intended effects are partly achieved, though the qualityenhancingassumption finds little support in caring research. The assumption that thesupervised parties will improve their compliance with laws and regulations has some validity,but this compliance is temporary and confined to the aspects of eldercare beingsupervised. Twenty-four interviews with the chairs of Social Welfare Committees andcare unit managers provide empirical support for all but two intended effects. SSV hasnot increased ‘awareness of national regulative demands in eldercare’ or contributed to‘general quality improvement in eldercare’. Four unintended effects of SSV were also recognisedin the interviews—for example, unsupervised caring activities were less prioritised.The authors conclude that, although SSV does little to improve eldercare quality, itis needed for transparency and accountability as well as to hold local governments andpublic and private service providers to account for compliance with national statutes.