The aim of this study was to analyse the effect of the visiting-scientist approach supported by conceptual change activities on high school students' images of scientists and perceptions of gender and risks that scientists take. Twenty-five students attending 10th grade in the 2017-2018 academic years participated in the study. A quasi-experimental model with a pretest and a post-test without a control group, one of the quantitative research techniques, was used. In the implementation, activities based on conceptual change and the visiting-scientist approach of were carried out. To determine students' scientist images, A 'Draw-a-Scientist-Test' and a 'Scientist-in-Images-Scale' were administered before and after the implementation, and interviews exploring their drawings were conducted. Similarly, the 'Gender-of-Scientists-Perception-Scale' and 'Risks-of-Being-a-Scientist-Perception-Scale' were conducted to determine students' perceptions of the gender of scientists, and the risks encountered by the scientists. A descriptive analysis approach was used for the analysis of qualitative data collected before and after the implementation, and a Paired-Sample t-test and Wilcoxon signed-rank test were used for the analysis of quantitative data. As a result of the analysis, it was found that, after the implementation, students thought of the scientist less stereotypically and their roles less risky than they believed before.