BACKGROUND: South African psychiatric hospitals' inpatient average length of stay is approximately 220 days. Inpatient care accounts for over 80% of the mental national healthcare budget. However, there is limited research on factors associated with length of stay (LOS) in tertiary psychiatric hospitals. AIM: To determine the threshold for long-stay and describe the socio-demographic and clinical profile of long-stay patients admitted to a tertiary psychiatric hospital. SETTING: Townhill Hospital: a tertiary psychiatric hospital in Pietermaritzburg, KwaZulu-Natal, South Africa. METHODS: A retrospective review of clinical records of admissions between January 2019 and January 2020 was conducted. Information on LOS, sociodemographic and clinical factors was collected. The interquartile range (IQR) of LOS in days was calculated, with patients above 75th percentile classified as long-stay patients. RESULTS: In total, 326 records were included. The 75th percentile LOS was 120 days. Eighty-three patients (25.46%) had a stay of 120 days or longer. The median LOS was 73 (IQR 49-120) days. Factors associated with long-stay included being male ( CONCLUSION: Psychotic disorders and associated factors are key contributors to long-stay hospitalisations. CONTRIBUTION: This study highlights the burden of inpatient care for psychotic disorders and the need for interventions that optimise care and promote remission. To reduce the economic impact of prolonged hospitalisations, early intervention and enhanced community-based mental healthcare services focused on psychotic disorders are recommended.