Background: Physiotherapists are trained to manage patients with physical needs, but because of limited training at an undergraduate level in mental health, patients may not receive holistic care. This lack of knowledge often can deny people living with a mental illness (PLWMI) the potential benefits of physiotherapy treatment and exercise.Objectives: Our study conducted in the KwaZulu-Natal province of South Africa aimed to determine the knowledge, attitudes and perceptions of physiotherapists working in the Department of Health (DoH) in KwaZulu-Natal, South Africa, towards mental health, and to determine whether their undergraduate training prepared them to manage PLWMI.Methods: A mixed-method design was employed. The Attitudes to Psychiatry (ATP-30) questionnaire was distributed to 153 physiotherapists in KwaZulu-Natal. Focus groups were conducted to ascertain whether their undergraduate training prepared them adequately to manage PLWMI.Results: A total of 124 physiotherapists completed the questionnaires. The mean ATP-30 scores was 103.70 (SD = 11.71). Females had slightly higher ATP-30 scores than males. Physiotherapists indicated in the focus groups that they received limited training about mental health at an undergraduate level.Conclusion: Physiotherapists working in the KwaZulu-Natal public sector have a positive attitude towards mental health and managing PLWMI. Participants expressed the need for the inclusion of theoretical and practical knowledge about mental health in the undergraduate curriculum and postgraduate courses related to this topic.Clinical implications: The outcomes of this study show the importance of the inclusion of mental health in the undergraduate physiotherapy programme. Exposure to the theoretical and practical knowledge of mental health during the undergraduate physiotherapy programme will assist qualified physiotherapists better manage PLWMI. Future studies should be conducted in the other provinces and in the private practice setting in South Africa, so as to compare the results.