Background: Climate changes are the greatest threat to public health in the twenty-first century, which put pregnant women and their developing fetuses at serious risk. Pregnant women's health may be improved by educating them about the hazards involved in their pregnancy. Aim: To evaluate effect of educational program regarding climate changes on knowledge, attitudes and practices of pregnant women. Design: A quasi-experimental study design one group (Pre-posttest) was used to fulfill this study. Setting: This study was conducted at Obstetrics and Gynecological Outpatient Clinic in Benha University hospitals. Sample: A purposive sample of 120 pregnant women according to inclusion criteria was included in the study. Tools: Four tools were used for data collection. Tool (1): A self-administered questionnaire. Tool (2): Maternal knowledge questionnaire. Tool (3): Modified Likert scale. Tool (4): Maternal reported practices. Results: There were highly statistically significant difference between the results of the post-intervention phase compared with pre-intervention about knowledge, attitudes and practices regarding climate changes and heat stress. Conclusion: There was a marked improvement in pregnant women's total knowledge, attitudes and practices regarding climate changes and heat stress after implementation of educational program. Recommendation: Dissemination of the current research educational program to all antenatal clinics and maternity hospitals at Benha city.