Building trust and involving service-users in the design and delivery of their services are core values in social work. If persons with disabilities are to enjoy the same rights and opportunities as everyone else, they too must be involved and be able to trust their caseworker. Based on a mixed-methods survey and interview study, this paper explores an alleged gap between the conceptions about casework concerning persons with disabilities among a. Danish caseworkers and b. service-users with disabilities. Based on two surveys, among service-users (N=1,427) and cross-municipal caseworkers (N=428), respectively, we find significant gaps between their perceptions on service-user involvement and their levels of trust in the services for persons with disabilities. Drawing on semi-structured interviews with persons with disabilities (N=20) and municipal caseworkers from four different human services departments (N=10), a series of barriers and opportunities for improving their encounters are presented. Overall, they show that trust between welfare systems and service-users is influenced by a complex interplay of individual, relational, situational and organizational factors. Knowledge gained from this study will help qualify municipal service provision for and with persons with disabilities in general, and particularly by directing attention to core dilemmas in social work challenging service-user involvement and trust.