Abstract. T  The aim of the current study was to explore the effect of a proposed instructional program based on phenomena to develop scientific argumentation skills in the science curriculum among a sample of intermediate school students. The instructional program was developed around the phenomena related to environmental balance and climate change, among first-grade intermediate school female students in Saudi Arabia.  . The experimental approach was used with a quasi-experimental design. Data was collected using the scientific argumentation skills test. The results emphasized the effectiveness of the proposed program in developing scientific argumentation skills related to assertions, evidence, and  justification. This shows that learning based on phenomena can contribute to the development of scientific argumentation skills, as it involves the development and analysis of claims by learners, examination of evidence, and providing appropriate justifications for the phenomena. This contributes to deepening their understanding of these phenomena and their ability to predict them. The study recommended utilize the proposed program based on phenomenon-based learning in teaching science to first-grade intermediate school students in Saudi Arabia and expand its use across different educational stages. Incorporate phenomenon-based learning as a component of professional development programs for science teachers at all educational levels. Train science teachers to develop scientific argumentation skills.