Purpose Patients with severe mental disorder have health and social needs that require care. The aim of the study was to determine the main areas of perceived needs among inpatients with severe mental disorders and to identify risk factors of the group of patients with the greatest unmet needs. Patients and Methods A total of 150 patients with severe mental illness were assessed during admission prior to discharge from the hospital. Camberwell Assessment of Needs was used as evaluation measure, in addition to clinical status (The Brief Psychiatric Rating Scale), social functioning (Personal and Social Performance) and sociodemographic variables. A descriptive and a multivariate logistic regression analysis were used to analyse variables related to the group of patients with the highest number of unmet needs (≥3). Results Mean number of needs was 7.93, being 4.61 the mean number of needs met and 3.32 the needs unmet. The highest proportion of unmet needs were intimate relationships (44.0%), company (40.7%) and daytime activities (38.7%). A relationship was also found between the presence of three or more unmet needs and the following variables: Brief Psychiatric Rating Scale score (p=0.004), Personal and Social Performance score (p = 0.013), marital status (p=0.018), employment status (p=0.009) and voluntary admission (p=0.032). The multivariate model explained 29.5% of the variance (Nagelkerke’s R 2 : 0.295). Conclusion Treatments aimed at improving social relationships and daytime activities could be a good option for inpatients with many unmet needs.