ObjectivesThis study aimed to explore the service needs and preferences of frequent emergency department users with mental health and addictions concerns who participated in a brief intensive case management intervention.MethodsWe conducted semi-structured individual interviews with 20 frequent emergency department users with mental health and addictions challenges, 13 service providers involved in the delivery of a brief case management intervention, and a focus group with intervention case managers. Thematic analysis was used to explore perceived service user profiles, service needs and preferences of care.ResultsService users experienced complex health and social needs and social isolation, while exhibiting resilience and the desire to contribute. They described multiple instances of stigmatization in interactions with healthcare professionals. Components of the brief intensive case management intervention perceived to be helpful included system navigation, advocacy, intermediation, and practical needs assistance. Frequent service users valued relational responsiveness, a non-judgmental stance, and a recovery orientation in case managers.ConclusionInterventions for frequent service users in mental health may be enhanced by focusing on the engagement of formal and informal social supports, practical needs assistance, system navigation, advocacy and intermediation, and attention to the recovery goals of service users.