The purpose of this study was twofold: first to investigate the effect of conceptual change oriented instruction accompanied by concept cartoon worksheet with simulation on students’ conceptual understanding and second to remedy their misconceptions of direct current electric circuits. Participants were 139 pre-service science teachers from four intact classes. A quasi-experimental design was used in the study. The experimental group studied the concept with the application of concept cartoon worksheet and simulation, and the control group studied it with traditional instruction. Students’ conceptual understanding and misconceptions were measured by a tree-tired misconception test. It was administered as pre-and-posttest. There was no significant difference between the means of pre-test scores of experimental and control groups. The main effect of treatment on post-test scores was examined via ANCOVA with pre-test scores used as covariate. The frequency of each misconception was calculated for both groups, from pre to post-tests regarding all tiers of items. The analysis yielded a significant treatment effect on students’ post-test performances. The findings indicated that the conceptual change oriented instruction accompanied by concept cartoon worksheet and simulation is likely to be effective for conceptual understanding and decreasing most of students’ misconceptions in direct current electric circuits.