BACKGROUND: Treatment pressures encompass communicative strategies that influence mental healthcare service users' decision-making to increase their compliance with recommended treatment. Persuasion, interpersonal leverage, inducements, and threats have been described as examples of treatment pressures. Research indicates that treatment pressures are exerted not only by mental healthcare professionals but also by relatives. While relatives play a crucial role in their family member's pathway to care, research on the use of treatment pressures by relatives is still scarce. Likewise, little is known about other strategies relatives may use to promote the treatment compliance of their family member with a serious mental health condition. In particular, no study to date has investigated this from the perspective of relatives of people with a serious mental health condition. AIM: The aim of this study was to answer the following research questions: Which types of treatment pressures do relatives use? Which other strategies do relatives use to promote the treatment compliance of their family member with a serious mental health condition? How do treatment pressures relate to these other strategies? METHODS: Eleven semi-structured interviews were conducted with relatives of people with a serious mental health condition in Germany. Participants were approached via relatives' self-help groups and flyers in a local psychiatric hospital. Inclusion criteria were having a family member with a psychiatric diagnosis and the family member having experienced formal coercion. The data were analyzed using grounded theory methodology. RESULTS: Relatives use a variety of strategies to promote the treatment compliance of their family member with a serious mental health condition. These strategies can be categorized into three general approaches: influencing the decision-making of the family member; not leaving the family member with a choice; and changing the social or legal context of the decision-making process. Our results show that the strategies that relatives use to promote their family member's treatment compliance go beyond the treatment pressures thus far described in the literature. CONCLUSION: This qualitative study supports and conceptually expands prior findings that treatment pressures are not only frequently used within mental healthcare services but also by relatives in the home setting. Mental healthcare professionals should acknowledge the difficulties faced and efforts undertaken by relatives in seeking treatment for their family member. At the same time, they should recognize that a service user's consent to treatment may be affected and limited by strategies to promote treatment compliance employed by relatives.