The problems found in biology learning in several schools in Pekanbaru are that students find it difficult to understand the material on the body's defense system, learning media are not varied and interactive, and the majority of students have a visual learning style, so learning media that can facilitate this learning style are needed. The material on the body's defense system is difficult to see directly and contains scientific terms that are difficult to understand. The development of learning media with attractive visualizations is a solution to these problems. The purpose of this study was to produce valid and high-quality flash card learning media on the immune system for 11th grade high school students. This study was conducted at the Biology Education Study Program, Faculty of Teacher Training and Education, University of Riau and SMA Negeri 8 Pekanbaru from January to June 2025. The type of research used was Research & Development (R&D) using the ADDIE model. This research was only carried out up to the development stage. The validation results showed a very valid category with an average score of 3.82. The results of limited trials I and II showed a very valid category with average scores of 3.87 and 3.89. The quality of the flash card learning media was assessed based on the average results of the validation and limited trials. The quality results showed an average score of 3.86 with a very good category. It can be concluded that the flash card learning media on the subject of the body's defense system has very valid validity and very good quality, making it suitable for use in biology learning.