Background: Cooperative learning is an active learning approach in which students work together in small groups to complete an assigned task. Students commonly find the subject of "physical and chemical changes" difficult and abstract, and thus they generally have many misconceptions about it. Purpose: This study aimed to investigate the effects of jigsaw cooperative learning activities developed by the researchers on sixth grade students' understanding of physical and chemical changes. Sample: Participants in the study were 61 sixth grade students in a public elementary school in Izmir, Turkey. Design and methods: A pre-test and post-test experimental design with a control group was used, and students were randomly assigned to the experimental and control groups. Instruction of the subject was conducted via jigsaw cooperative learning in the experimental group and via teacher-centered instruction in the control group. During the jigsaw process, experimental group students studied the subjects of changes of state, changes in shape and molecular solubility from "physical changes," and acid-base reactions, combustion reactions and changes depending on heating from "chemical changes" in their jigsaw groups. Results: The concept test results showed that jigsaw cooperative learning instruction yielded significantly better acquisition of scientific concepts related to physical and chemical changes, compared to traditional learning. Students in the experimental group had a lower proportion of misconceptions than those in the control group, and some misconceptions in the control group were identified for the first time in this study. Conclusions: Jigsaw cooperative learning is an effective teaching technique for challenging sixth grade students' misconceptions in the context of physical and chemical changes, and enhancing their motivation, learning achievements, self-confidence and willingness in the science and technology lesson. This technique could be applied to other chemistry subjects and other grade levels.