BackgroundThe population with severe mental disorders (SMD) is a frequent user of emergency services. Situations of psychiatric decompensation can have devastating consequence and can cause problems in getting urgent medical care. The objective was to study the experiences and needs of these patients and their caregivers regarding the demand for emergency care in Spain.MethodsQualitative methodology involving patients with SMD and their informal caregivers. Purposive sampling by key informants in urban and rural areas. Paired interviews were carried out until data saturation. A discourse analysis was conducted, obtaining a codification in categories by means of triangulation.ResultsForty-two participants in twenty-one paired interviews (19 ± 7.2 min as mean duration). Three categories were identified. 1º Reasons for urgent care: poor self-care and lack of social support, as well as difficulties in accessibility and continuity of care in other healthcare settings. 2º Urgent care provision: trust in the healthcare professional and the information patients receive from the healthcare system is crucial, telephone assistance can be a very useful resource. 3º Satisfaction with the urgent care received: they request priority care without delays and in areas separated from the other patients, as well as the genuine interest of the professional who attends them.ConclusionsThe request for urgent care in patients with SMD depends on different psychosocial determinants and not only on the severity of the symptoms. There is a demand for care that is differentiated from the other patients in the emergency department. The increase in social networks and alternative systems of care would avoid overuse of the emergency departments.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12875-023-02078-6.