STEAM is a concept that is made up of the initials of the words science, technology, engineering, arts and mathematics. The aim of this study is to determine the effect of STEAM-based teaching activities on students' lesson achievements and attitudes in secondary school Visual Arts lessons. The study was carried out in a private secondary school in Mersin. The study, which was carried out with 24 students in the experimental and 24 control groups for 5 weeks, was designed according to the experimental model with the control group, which is one of the quantitative research methods. In the study, Secondary School Visual Arts Lesson Acquisition Test and Attitude Scale towards Visual Arts Lesson were used as data collection tools. According to the research findings, there were significant differences in favor of the experimental group in the posttest achievement and attitude scores of the experimental group, in which activities based on the STEAM teaching approach, and the control group, in which traditional teaching was applied.