The purpose of this study was to investigate both the individual and relative effectiveness of two conceptual change interventions, gender and their interactions on preservice science teachers' conceptual understanding and their misconceptions in mechanical waves. The interventions are conceptual change texts enriched with concept cartoons (CCTCC) and 5E learning model enriched with simulation activities (5ESA) respectively. Participants are 66 sophomores from two intact classes. A quasi-experimental design was used as a research methodology. One group studied the concept of mechanical waves with the CCTCC and the other studied it with the 5ESA. Students' conceptual understanding levels and misconceptions were measured by a Four-Tier Mechanical Waves Misconception Test as pre and post-test. Preliminary analysis indicated that there was no significant difference among the intervention groups' pre-conceptual understanding levels. Individual effects of the treatments from pre to post-tests were investigated by paired-sample t-tests and the main effects of the treatments, gender and their interactions on post-conceptual understanding levels were examined via two-way ANOVA. The results of t-tests showed that both treatments significantly affected learners' conceptual understanding levels individually. ANOVA results yielded a significant treatment effect on behalf of the CCTCC, but the effects of the gender and gender*treatment interaction on students' post-conceptual understanding levels were insignificant. Findings showed that the conceptual change approach accompanied by conceptual change text enriched with concept cartoons is likely to be more effective for increasing students' conceptual understanding level and decreasing their misconceptions in mechanical waves.