Even though many studies have been conducted regarding realistic mathematical concepts, there is only a little research on their implementation in vocational mathematics learning. This study aims at producing a mathematics instructional materials development model. This study was a research and development and involving students (Diploma III and Diploma IV) of vocational universities in Bali who were selected by purposive random sampling. This development resulted in a conceptual model involving four stakeholders (tetra -helix) of development research, such as researchers, industry workers, teachers, and students. The tetra -helix model concept based on vocational realistic education is a model for developing mathematics instructional materials which can be used at a vocational institution in the form of textbooks, job sheets, syllabus, and lesson plans. They integrate the ma thematical concepts learned with their realistic applications in industry (tourism, engineering, and e-commerce).