Context: Climate change is an unavoidable issue that poses a significant risk to human health on global scale exacerbating respiratory allergic diseases and refers to long-term changes in average weather patterns over time. Aim: To evaluate the effect of climate changes program on knowledge and health related behaviors of patients with respiratory allergic diseases.  Method: The study used a quasi- experimental design, specifically employing a pre/post-test methodology on a purposive sample of (80) patients with respiratory allergic diseases visited the allergy and immunology outpatient clinic through four months at Benha University Hospital, Qualubyia Governorate, Egypt. Tools: Three tools were utilized for data collection: Structured interview questionnaire, patients' knowledge assessment and patients' climate changes health-related behaviors scale. Results showed a statistically significant increase in the total patients' knowledge level both immediately and post 3 months of climate changes program implementation (P= ≤0.05). There was a statistically significant enhancement in the total patients' health related behaviors level, whereas 86.2% of the studied patients had unsatisfactory health-related behaviors preprogram implementation, but improved to be satisfactory as observed in 72.3% & 68.8% of them immediately post and post 3 months of program implementation, respectively (P= ≤0.05). Besides, a positive significant correlation between patients' total knowledge score and total health related behaviors pre and post 3 months of program implementation, as well as a highly significant correlation immediately post program implementation (P<0.001^**). Conclusion: The implementation of climate changes program resulted in a significant and positive effect on the knowledge and health related behaviors of patients with respiratory allergic diseases. Recommendations: Further researches and studies are needed to focus on identifying new approaches of climate changes program among patients with respiratory allergic diseases to enhance their health-related behaviors.