Background: Using evidence-based interventions (EBIs) is a basic premise of contemporary social services (e.g., child and family social services). However, EBIs seldom fit seamlessly into a specific setting but often need to be adapted. Although some adaptions might be necessary, they can cause interventions to be less effective or even unsafe. The challenge of balancing adherence and adaptations when using EBIs is often referred to as the adherence and adaptation dilemma. Although the current literature identifies professionals' management of this dilemma as problematic, it offers little practical guidance for professionals. This research aims to investigate how the adherence and adaptation dilemma is handled in social services and to explore how structured decision support can impact the management of the dilemma. Methods: The design is a prospective, longitudinal intervention with a focus on the feasibility and usefulness of the structured decision support. The project is a collaboration between academic researchers, embedded researchers at three research and development units, and social service organizations. A multi-method data collection will be employed. Initially, a scoping review will be performed, and the results will be used in the development of a structured decision support. The decision support will be further developed and tested during a series of workshops with social service professionals. Different forms of data-focus group interviews, questionnaires, and documentation-will be used on several occasions to evaluate the impact of the structured decision support. Qualitative and quantitative analysis will be performed and usefulness for practice prioritized throughout the study. Discussion: The study will contribute with knowledge on how the adherence and adaption dilemma is handled and experienced by social service professionals. Most importantly, the study will generate rich empirical data on how a structured decision support impacts professionals' management of adherence and adaptions. The goal is to produce more strategic and context-sensitive implementation of EBIs in social service, which will increase value for service users.