Background: Professional quality of life amongst nurses in psychiatric observations units may be affected by working conditions such as an overflow of mental health care users (MHCUs), a shortage of nurses, lack of specialised staff and inadequate infrastructure to accommodate MHCUs amongst others.Aim: The aim of the study was to investigate the professional quality of life amongst nurses in psychiatric observation units.Setting: The study was conducted in psychiatric observation units in eight hospitals in the Metropole District Health Services in the Western Cape.Method: A quantitative descriptive survey design using the Professional Quality of Life (ProQoL version 5) questionnaire was conducted with an all-inclusive sample of 175 nurses. The ProQoL has two scales, namely, the compassion satisfaction and the compassion fatigue. Compassion fatigue includes two subscales, burnout and secondary traumatic stress. Ethics to conduct the study was obtained from the Research Ethics Committee at the university and the Department of Health in the Western Cape.Results: A response rate of 93% (n = 163) was obtained. Respondents reported moderate compassion satisfaction. Psychiatric nurse specialists and registered nurses reported lower compassion satisfaction than enrolled nurses and nursing assistants. This came with moderate levels of burnout and high levels of secondary traumatic stress, with enrolled nurses and enrolled nursing assistants reporting lower levels than the other professional groups.Conclusion: Psychiatric nurse specialists and registered nurses experienced higher burnout and secondary traumatic stress and lower compassion satisfaction than the lower categories of nurses.