Objective: To define the safe transition process from hospital to community of patients with chronic mental disorders and their families. Method: This was an action research study included in the constructivist paradigm. The participants in the study were nurses from a psychiatry service and from primary healthcare services. Results: After the identification of causes of continuity fragmentation, the following items emerged from the participants’ speeches: a) two criteria categories for safe transition (those associated with health status, dependence level, and self-care capacity of patients, and those associated with knowledge and competence level of informal caregivers); b) the design of an algorithm to facilitate clinical decision-making. Final considerations: In order to promote adherence to therapeutic treatment in the hospital-community transition, treatment plans must include patients and their families, and improve communication networks and support among care levels.