The purpose of the current study was to determine the effect of teaching astronomy through augmented reality (AR) on the achievement and interest level of gifted students and their opinions about AR applications. The current study was conducted in line with the explanatory sequential mixed-methods design. The study group of the current research was comprised of 51 gifted students (26 in the control group and 25 in the experimental group) attending a Science and Arts Centre (B?LSEM). In the application process, the astronomy teaching activities supported with AR were used in the experimental group while the astronomy teaching activities suggested in the official science curriculum of the middle school 7th grade were used. The data of the study were collected by using an Astronomy Achievement Test and the Scale of Interest in Astronomy as a pretest and posttest and an AR Interview form administered only to the experimental group students at the end of the application. The statistical analyses of the quantitative data revealed that before the experimental application, the experimental and control groups were equal in terms of astronomy achievement and interest in astronomy. After the completion of the application, however, significant differences were found for both the experimental and control groups in favor of the posttest. Moreover, significant differences were also found in the posttest in favor of the experimental group in terms of both astronomy achievement and interest in astronomy. In other words, AR-supported astronomy teaching activities positively affected the experimental group students’ astronomy achievement and interest in astronomy. Furthermore, the experimental group students expressed many positive opinions about the AR applications within the categories of technical features and cognitive and affective features. The experimental group students wanted the use of AR applications in the teaching of other science subjects and other courses.