The main objective of this study was to compare the effectiveness of three STEM approaches in implementing STEM activities in lower secondary school students based on knowledge and scientific creativity. A pre-posttest experimental design was adapted. Six classes with almost similar learning conditions were randomly selected and each class was assigned as a group, in which two groups followed the Stand–alone engineering design approach, two adopted the 5E-EDP approach, and two classes used the Jigsaw learning approach. The data were collected from the tests before and after the experiments and were statistically analyzed. The findings revealed that these three approaches enhanced the students’ gains in both knowledge and scientific creativity. Despite the overall progress, there existed a statistical difference among these models in their effects on the students’ knowledge and scientific creativity. While 5E-EDP and Jigsaw learning approach were proven to make substantial progress in these factors, the Stand-alone engineering design scored less significance. The study also showed that there was a statistical difference between the Stand-alone engineering design approach and Jigsaw learning approach. The respective second approach formed a foundation for better performance of the students’ knowledge and scientific creativity compared to the first one. Each approachhas its own value in enhancing students’ knowledge and scientific creativity. The result of this study could be a hint for STEM educators to apply appropriate methods in similar contexts to boost achievements.