This study aimed to investigate the awareness and views of teachers from different disciplines who received in-service STEM training about STEM education. To this end, the study employed a mixed methods research design in which both quantitative and qualitative research approaches are used. For the quantitative phase of the study, the sample was composed of 64 teachers from the different branches. The teachers were sampled using convenience sampling. For the qualitative phase of the study, the teachers were chosen using criterion sampling. The sample was drawn of 16 teachers who had a high, moderate or low level of awareness. The quantitative data were collected using the "STEM Awareness Scale" and the qualitative data were collected using a semi-structured interview form. The analysis results showed that teachers' awareness of STEM increased after the in-service training. The teachers held the view that using the STEM approach in their classes is beneficial to, themselves, students, and the country and the effective implementation of STEM education depends on the elimination of shortcomings such as the lack of time, materials, and workshops.