This study aimed to develop and assess strategies for integrating a green curriculum into Indonesian elementary science education to improve environmental awareness and eco-friendly culture among students. Utilizing research development design, the research began with a needs analysis from five elementary schools, followed by a quasi-experiment in one selected school. Environmental awareness and eco-friendly culture were measured at the end of the learning period in both control and experimental groups, with a t-test revealing significant differences. The experimental group showed higher environmental awareness and eco-friendly culture scores than the control group than the control group (p < 0.05). These results confirmed that integrating environmental responsibility into student activities in science education, such as caring for plants or animals, significantly enhances their environmental stewardship. This study provides practical and theoretical insights into green curriculum integration, especially in developing countries, and highlights the importance of incorporating ecological responsibility projects in education to promote sustainable behaviors. The findings can inform educational practices, curriculum development, and policymaking in sustainable education.