Aims and method To describe the clinical and demographic characteristics of all in-patients experiencing delayed discharge over 3 months in an English urban mental health National Health Service trust. We carried out a cross-sectional case record study with care coordinator questionnaire. Results Overall, 67 in-patients with delayed discharge occupied 18.6% of acute beds. Older in-patients were White, diagnosed with dementia and experienced relatively short admissions. Younger in-patients were often of Black and minority ethnic background with a psychotic diagnosis and long service contact, and sometimes experienced very long admissions. They were similar to a long-stay comparison group. The whole cohort was socially isolated and marginalised, and frequently misused alcohol. Clinical implications People with complex mental health problems can experience long stays in acute care settings. This particularly affects people with psychosis who are isolated in the community. Alcohol misuse is the most common complicating factor. There are insufficient community-oriented rehabilitation services to meet these patients’ diverse needs.