The present research has made a comparative study of textbooks used for science and chemistry and the environment in Iran and those used for science and chemistry in the United States of America, India and Australia. The statistical population consisted of the textbooks used in the four countries mentioned above. George Bereday’s method for comparative research has been used. The sources used for data collection have been the textbooks and curricula of the countries mentioned above, acquired by means of the Internet or library resources. Then, the content was categorized into sub-components in numerous checklists based on the elements of the curriculum and the main designated environmental components, and the relevant content was extracted and studied. The results of this study pointed out that, although Iranian textbooks have covered most of the topics relevant to environmental education, their content is seldom practical. Moreover, based on the findings of this research, the content pertaining to environmental education in Iranian textbooks is generally informative and news-like in nature and very little attention has been given to critical thinking, analysis or examining environmental issues from various aspects. Therefore, it is recommended that the environmental content in Iranian textbooks be enriched and modified by paying attention more attention to practical topics and also critical thinking, problem-solving skills, real, domestic case studies, and the analysis of environmental events from various aspects.