The "Organic Chemistry in Action!" ("OCIA!") program is a set of teaching resources designed to facilitate the teaching and learning of introductory level organic chemistry. The "OCIA!" program was developed in collaboration with practicing and experienced chemistry teachers, using findings from Chemistry Education Research (CER). The program was developed as an alternative mode of teaching the prescribed high school organic chemistry curriculum in Ireland. The program aims to improve learners' attitudes towards, interest in and understanding of organic chemistry. The "OCIA!" program has been trialed with 87 students in six high schools. The effectiveness of the program was evaluated using three methods: feedback from the chemistry teachers in the experimental group (n = 6), feedback from the students in the experimental group (n = 87) and quasi-experimental comparison with students in a control group (n = 117). The evaluation has shown that this project was effective in improving the students' attitudes towards, interest in and understanding of organic chemistry. This evaluation identifies the challenges and opportunities in implementing CER in designing Chemistry curricula for high school classrooms. The integration of CER in practice requires collaboration between all parties responsible for designing, teaching and assessing school Chemistry. It is hoped that the evidence from this intervention can be used to encourage the use of evidence-based best practice in high school chemistry classes internationally. The approach is also useful for introductory organic chemistry courses at university.