Building on existing literature, the authors draw the landscape of psychiatric emergencies, and focus on borderline personality disorder, frequently encountered, and strongly linked to death by suicide. A review of knowledge in terms of diagnosis, prognosis, etiology, and treatment, as well as their own experiences, lead them to propose areas of progress that would secure the patient's care pathway. The evolution of society has led psychiatric emergency departments to play the role of a safety net and an entry point to the mental health system. Borderline personality disorder is one of the most common pathologies encountered in psychiatric emergencies. It represents a major concern, long characterized by an often dramatic evolution, and by the human and economic stress it generates. However, since the 1990s, knowledge of this disorder has been refined, and today there are various means of evaluation, good clinical practices and psychotherapeutic treatments, thanks to which significant and lasting improvement is possible. Recent studies highlight the crucial role of hospital caregivers, and the benefit of consolidating their skills by providing them with the knowledge and tools specific to this disorder. They also converge on the interest of setting up specific emergency treatment modalities, particularly highly structured, safe and empowering for the patient, in order to improve their effectiveness. The authors suggest that a case formulation model for persons with borderline personality disorder in emergency would make it possible to activate these two levers of progress, while improving collaboration between hospital and outpatient care. This would also address their main concern of optimizing the patient's therapeutic pathway and reinforcing adherence to treatment that could bring remission, and should be supported by data from empirical research.