Ample studies have confirmed that the concepts of Community of Practice and Lesson Study can effectively develop professional development, especially in the design of learning. This positive impact on learners is also evident. Therefore, this study aimed to examine the results that occurred with students who learned from teachers who used activities based on the concepts of Community of Practice and Lesson Study, focusing on studying cognitive competencies, including creative thinking, problem-solving, and analytical thinking. The study involved 60 elementary school students from 5 different science classrooms, taught by 5 collaborating teachers. In this research, two communities of practice were established: (i) Community of Practice A (CoP A), consisting of teachers with varying teaching experiences and teaching fifth-grade students, and (ii) Community of Practice B (CoP B), consisting of teachers with similar teaching experiences and teaching sixth-grade students. Data for this study was collected quantitatively through measures of analytical thinking, problem-solving, and creative thinking. The research results revealed that the students' thinking competencies improved significantly. In CoP A, the students demonstrate a positive trajectory in developing competencies across all thinking competency, particularly excelling in analytical thinking. In problem-solving and creative thinking, the majority exhibit proficiency ranging from high to moderate levels. Meanwhile, in CoP B, most of the students show positive progress in thinking competencies, with high and moderate proficiency in problem-solving and creative thinking. However, there's a noticeable trend of moderate to low emphasis on analytical thinking.