Background: Climate change and sustainability are commonly recognized as the two global health challenges that will have the greatest impact on people's health in the next 10 years. To both mitigate and adapt to the consequences of climate change on the healthcare sector, nurses are crucial. Aim: This study aimed to investigate the effect of awareness programs regarding climate change and sustainability development on nursing internship students' knowledge. Methods: A one-group quasi-experimental research design was used to achieve the aim of this study. Setting: The current study was carried out at Sohag University Hospitals. Sample: A convenience sample involved 200 nursing internship students who were enrolled in the current study. Three tools were used to collect data: Tool (I): Nursing internship students' personal data, Tool (II): Nursing internship students' knowledge about climate change, and Tool (III): Nursing internship students regarding green management and sustainability practices. Results: The current study results revealed that 60% of nursing internship students had poor knowledge of pre-awareness program implementation, while 85% of them had good knowledge, post post-awareness program implementation, with a highly significant difference at p-value <0.01**. Also, 80% of nursing internship students with pre-awareness program implementation had unsatisfactory practices, while 70% of them had post-awareness program implementation satisfactory practices, with a highly significant difference at p-value <0.01**. Conclusion: The awareness program has a positive effect on nursing internship students' knowledge and practices about climate change and sustainability than they did before the awareness program. Recommendations: Encourage nursing students to take part in continuing education programs concerning sustainability and climate change.