This study was designed as a case study. Participants were 12 senior pre-service science teachers (PSTs), who took theoretical and practical courses about STEM education and socio-scientific issues (SSIs) during their education at a state university. For the study, in the first 4 weeks, theoretical courses on SSIs and STEM education were carried out. Afterwards, PSTs were asked to choose a SSI and configure this issue as a problem statement to perform a STEM activity. Participants were given a total of 3 weeks to determine the issue and prepare the STEM activity, and the researchers of the study gave systematic feedback during this period. Then, starting from the fifth week of the study, groups started to implement their STEM activities in the class, where their peers were assigned as their students. The activity plans they prepare, the field notes taken by the researchers during the implementation of the activities and the semi-structured interviews about the opinions of the PSTs on the use of SSI in STEM education were the data sources of the study. Findings revealed that PSTs found establishing STEM problem situations over SSIs suitable since they provide features such as conformity to real life, having multiple criteria and providing compatibility with other disciplines. Moreover, after their practices, they pointed out that the activities enabled both the teaching of the SSI and the integrated teaching to be carried out. As a conclusion, it is recommended to use socio-scientific problem situations to perform STEM education.