The purpose of this study is to investigate the effect of grade level on high school students’ attitudes toward chemistry as a school subject. Attitude Scale Toward Chemistry developed by Geban & Ertepınar (1994) was administered to collect data. The sample of the study was composed of 197 high school students from different grades that ranged from Grade 9 to 11. Principal component analyses revealed two dimensions of the scale for this data set and these dimensions were labeled as “enjoyment” and “importance”. Cronbach Alpha reliability coefficient of the scale was computed as .93. MANOVA results indicated that grade level had significant effects on high school students’ attitudes toward chemistry as a school subject in terms of both enjoyment and importance dimensions. Post Hoc analyses revealed that there is significant mean differences between Grade 9 and Grade 10 students’ attitudes toward chemistry as a school subject on both dimensions.