OBJECTIVE: Persons who cope with serious mental illness (SMI) without immediate physical risk to themselves or others have the right to refuse to be treated. Treatment refusal has implications not only for the individual but also for the family, especially the primary caregivers. Still, less is known about the phenomenon of family burden while coping with a situation where the family member with SMI refuses treatment and lives in the community. The present study aimed to understand and describe the caregivers' lived experience of family burden in the context of treatment refusal among their relatives. METHODS: Using a descriptive phenomenological qualitative approach and a semi-structured interview guide, 15 family caregivers of persons with SMI refusing to receive medicinal treatment and rehabilitation services were interviewed. Inductive thematic analysis was conducted on the interview transcripts. RESULTS: The caregivers described a complex experience of ongoing and intense burden that had a negative impact on the family cohesion and the caregivers' well-being. Four themes related to the perceived reasons for treatment refusal, the caregivers' experience of the family burden and cohesion, and coping with this situation were identified. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: The findings demonstrate the unique family burden experienced by the caregivers, mainly as they are the only ones supporting the individual with SMI who refuses treatment. Practitioners should support these families throughout their coping process-from understanding the reasons for the refusal of treatment to continuous support in their daily coping by locating the control of the situation on the family level. (PsycInfo Database Record (c) 2025 APA, all rights reserved).