BACKGROUND: As health care technologies continue to advance rapidly, resulting in improved standards of practice, it is essential for health care professionals to continually expand on their current skills and knowledge. We describe here an initiative to use open education resources to provide ongoing education in radiation medical sciences and imaging. AIMS: The aim of this study to design an interactive, engaging, multilevel radiation medical physics resource, which is fully open to the public, and functional on all types of computing devices. Our primary target audiences are students and workers in medical radiation technology and other health care professionals as part of their continuing professional development. DESIGN AND DEVELOPMENT: The three tasks of design, development, and content creation were most efficiently performed in parallel wherever possible. A modern responsive web design was adopted to target all desktop and mobile devices. Only open-source tools and libraries were used in developing the OpenPhys website. OVERALL WEBSITE DESIGN AND NAVIGATION: The homepage is a modern tile-based design containing one coloured tile for each lesson. Clicking anywhere on a coloured lesson tile will open up a two-dimensional interactive concept map linking to content pages. Currently, 10 lessons are available online ranging from the electronic structure of the atom to MRI basics: "NMR" and "Inside a Pixel". Lesson pages include text, images, graphics, equations, quizzes, and interactive animations. USER FEEDBACK: An online questionnaire was emailed to current radiation therapy students at the University of Alberta and alumni regarding the functionality and navigation of the website. DISCUSSION/CONCLUSION: To our knowledge, OpenPhys is the first open education resource specializing in radiation physics and medical imaging. We believe OpenPhys will fill existing gaps in the realm of physics education delivery and could be a component of a blended learning initiative. Future steps will include a formal evaluation of the website and content.