Climate change is increasingly recognised as a critical public health challenge, a perspective reinforced by its inclusion as Sustainable Development Goal 13. Given its significant disease burden, climate change should be reframed as a leading health priority, demanding an immediate and coordinated response from the health sector. The aim of the study was to assess the knowledge and attitudes of professional nurses in primary health care regarding climate change. The study was conducted in Nkangala District, Mpumalanga province. A non-experimental, descriptive and quantitative research design, employing a self-administered questionnaire, was used to collect data. A comprehensive sampling of the entire population was conducted in the Thembisile Hani Local Municipality, Nkangala District, Mpumalanga, because of the small population size. About 82% of the professional nurses in primary health care had knowledge regarding the effects of climate change, and 23% did not link climate change to diseases. Regarding nurses' attitudes and perceptions, approximately 66.2% strongly agreed that understanding the issue is crucial to providing effective patient care. In support, 29.8% agreed that it is essential to understand the issue to help patients, 3.3% were neutral, while 0.7% strongly disagreed and 0% disagreed. The findings of the study highlighted the importance of educating registered nurses about the mental health effects of climate change. It also emphasised the need to formally include climate change in the nursing curriculum, as many nurses currently depend on informal education to understand its implications. The results of the study will contribute new knowledge regarding climate change, its impact on health and its implications for the nursing profession. In addition, the study emphasised the importance of incorporating climate change into the nursing curriculum.