<p>This research examined preschool teachers’ knowledge and implementation of engineering-based STEM activities with the aim of understanding their attitudes and concerns regarding STEM education and their knowledge of classroom engineering practices as well as identifying the difficulties of incorporating engineering practices in the classroom. Most previous studies in this area have been conducted with secondary school students; there is relatively scarce literature addressing preschool teachers’ perceptions of the planning and implementation of engineering-based STEM programmes. To address that gap, interviews were conducted and observations were made to capture preschool teachers’ personal information, knowledge and perceptions, and practices and experiences in the implementation of engineering-based STEM activities. Thematic analysis was then conducted with an emphasis on the presence of recurrent patterns. The findings revealed that preschool teachers possess positive attitudes towards STEM education and appreciate its value for young children. Nevertheless, they face numerous problems, including shortages of materials, insufficient preparation, and uncertainty regarding how to introduce the teaching of engineering into potentially incompatible curricula. This study showed that the teachers found it important and necessary to receive more professional development support with a focus on STEM; educational authorities should offer more effective support for teachers to implement such activities.</p>