Background: The degree of informal caregiver involvement influences the self-management of individuals living with bipolar disorder (BD).; Objective: This article aims to provide a description of informal caregivers' learning experiences in self-management support of BD in order to guide professionals in tailoring future psychosocial and psychoeducational interventions.; Design: In-depth open interviews with 10 informal caregivers of patients with BD who followed treatment in the context of specialized outpatient bipolar care were conducted.; Results: Four learning phases emerged from the phenomenological analysis describing the informal caregivers learning process: (1) understanding BD, (2) overcoming the dilemmas in self-management support for individuals living with BD, (3) dividing tasks and responsibilities, and (4) acquiring a personal definition of self-management support for individuals living with BD.; Conclusion: By grasping the concept of BD, informal caregivers gradually learn how to overcome dilemmas resulting from living with someone with BD, and how to control the expression of emotions. They learn to reflect on the nature of conflicts and how to share the responsibilities of illness management with individuals living with BD and professionals. Mastering these skills eventually allows them to define and delimit their supporting informal caregiver role in the self-management of BD.; Practice Implications: Our findings provide information regarding the educational needs of informal caregivers to tailor counseling, and psychosocial and psychoeducational interventions in specialized outpatient care for individuals living with BD.