Purpose: Medical Massive Open Online Courses (MOOCs) are of interest for campus education. With growing interest in integrating medical MOOCs, their quality must be ensured. This however, has not been studied. We investigated if medical MOOCs meet the instructional design principles: problem-centeredness, activation, demonstration, application, integration, collective knowledge, collaboration, differentiation, authentic resources, feedback, and goal-setting. Methods: An overview of medical MOOCs and inclusion criteria were developed. Out of 410 MOOCs, 33 were selected. A data collection tool was compiled and calibrated. Investigators enrolled in selected MOOCs and coded presence of instructional design principles after examination of all course pages. Results: Application, authentic resources, problem-centeredness, and goal-setting were found to be present in many of the courses. Activation, collective knowledge, differentiation, and demonstration were present in less than half of the courses. Finally, integration, collaboration, and expert feedback were present in less than 15% of the courses. Conclusions: Medical MOOCs meet these principles in varying degree. Certain principles might be scarcely present due to a problematic fit with the MOOC concept or a need for further development in online settings. Assessment of instructional design quality is desired before integrating so that MOOC quality can be considered in relation to the quality of existing campus education.