The importance of enhancing entrepreneurial STEM education has become accentuated to foster sustainable, collegial, and innovative STEM practices. The study aimed to enhance high-school students' entrepreneurial skills, namely resourcefulness and problem-solving skills, and investigate their experiences and feelings of entrepreneurial STEM education. Three entrepreneurial STEM activities were implemented with 30 students in a private high school in Turkey. The qualitative data were collected through pre- and post-interviews and group reflective journals and analysed with content analysis. The quantitative data were collected through the Self-Control Schedule (SCS) and the Problem-Solving Scale (PS) and analysed through SPSS. The quantitative data indicated that the participants' average SCS results increased from 117.63 to 122.40 (no significant difference) and their average PS results increased from 130.00 to 135.55 (no significant difference) following an intervention. This may be because of participants' prior experiences or the number of participants attending the study. However, there were significant changes in the subscales of SCS and PS, showing that participants' approach-avoidance style (PS subscale) as well as planning of behaviour and control of emotions (SCS subscales) can be enhanced by implementing entrepreneurial STEM activities. The qualitative data showed that participants started to face their problems more and try to find them different solutions rather than avoiding them. The qualitative data also pointed to the changes in participants' capability of making connections between the subject disciplines and everyday life. Moreover, students found entrepreneurial STEM activities entertaining and helpful for improving understanding of chemistry topics. The study contributes to the field by bringing authenticity to STEM education by incorporating social and green entrepreneurship, supporting students' entrepreneurial skill development, and helping teachers and students make connections between STEM, real-world, and public.