Background and aims: Increasingly, efforts to counteract perceived problems in drug treatment at residential rehabilitation centres have come to rely on measures drawing on evidence-based practice (EBP). However, the Swedish media, government inquiries, and international research have identified a number of problems regarding both residential rehabilitation and EBP. This suggests that caution should be exercised when placing expectations on EBP. The aim of this study is to investigate how the responsible authorities have handled increasing demands for EBP with administrative control while facing critical evaluations of their steering and implementation efforts. The study examines the maturation of a widespread treatment ideology, which aims to be based on evidence, in a country known for its restrictive drug policy and its goal of becoming a drug-free society. Methods: Through a qualitative textual analysis of 17 years (2000-2016) of inquiries, directives, and authority archives we have traced the interplay between problem descriptions, intended goals, and implemented solutions. Findings: The analysis shows that the ambition to provide care and welfare based on EBP is still an ambition. Also, the authorities' control over the care actually provided still leaves room for improvement. Recurring criticism and the empirical material indicate that the expectations have not been met. Conclusions: We would like to suggest that continued frustration can be traced to the misconception that EBP is the opposite of values and ideology, and hence preferable. As drug treatment strives for scientific credibility to give it legitimacy, some types of evidence are preferred above others. We would like to suggest that we need to bring ideology to the fore, and openly discuss our restrictive policy goals and choices of evidence.