Open Science is gaining ground in all research fields, including health economics and outcomes research (HEOR). However, teaching Open Science is still in its infancy. This paper describes the design, implementation and evaluation of a teaching activity focusing on introducing Open Science during a Master's course during which participants have to develop a discrete event simulation. The teaching activity was organised as a series of lectures introducing different aspects of the Open Science philosophy and practices, such as good software coding practices, version control systems and reproducible research. The participants' increase in Open Science knowledge was elicited through a survey before and after the teaching innovation. After the teaching innovation, participants' knowledge of Open Science increased and they reported an improvement in Open Science-related skills, such as using a script-based statistical software, identifying and re-using open data, and collaborative script development. During the evaluation at the end of the course, the course participants mentioned that the Open Science-related content was interesting but would fit better within a course in which broader research-related content is taught. Based on this feedback, we will most likely narrow the scope of the Open-Science-related content in this course to Open Source Modelling which may better fit the scope of the course. This paper contains links to the teaching activities we developed and other resources which may be used to design teaching activities on Open Science. Herewith, we hope to inspire other teachers in including Open Science into their teaching.