BACKGROUND: Psychiatric patients in specialist units are more vulnerable to infections such as SARS-COV-2 (severe acute respiratory syndrome coronavirus 2) because of hospital infrastructure and patients' mental health. AIM: This study aimed to describe the psychiatric and medical profile, and the risk factors associated with more severe disease and clinical outcomes of coronavirus disease 2019 (COVID-19) in patients with severe mental illness (SMI) admitted to a specialist psychiatric hospital in South Africa between 01 April 2020 and 30 September 2021. SETTING: The study was executed at the Vàlkenberg Hospital (VBH), which is a government-funded, specialised psychiatric hospital. The hospital comprises 370 beds made up of 145 forensic service beds and 225 acute service beds. It provides in-patient and out-patient services. METHODS: Demographic and clinical information were collected for all VBH in-patients who tested positive for SARS-COV-2 from 01 April 2020 to 30 September 2021. RESULTS: A total of 254 participants tested positive for SARS-COV-2. The sample comprised 75% ( CONCLUSION: Contrary to early fears of high mortality among institutionalised SMI patients, most experienced mild COVID-19 illness and recovered. CONTRIBUTION: This descriptive study provided information on in-patients with COVID-19 disease at a specialised psychiatric hospital during the pandemic.