The purpose of this study is to investigate the effects of Augmented Reality (AR) intervention on students' spatial skills and academic achievement. The study was conducted in a freshman technical drawing course at Mechanical Engineering Department. An exploratory quasi-experimental method was used for the study. The study was conducted in two groups (Experiment-Control) as a quasiexperimental pre-post design. The pre-test results were used only to determine the control group and the experimental group. The research process was conducted within a four-week experimental period, including a one-week pilot study. The researchers and lecturers who are recognised experts prepared the instruments. The drawings of the experimental and control groups were evaluated using the evaluation criteria prepared by the two expert lecturers of the course. In the evaluation, two types of scores were given to the students, namely "Academic Achievement Score" and "Spatial Ability Score". Using ANOVA, the effects of AR intervention on students' spatial skills and academic performance were examined over three experimental periods. There was a significant main effect for both groups with a large effect size ([eta]2=0.253). However, it was found that there was no significant effect between the control group and the experimental group on spatial skills. However, it was found that there was a significant interaction effect providing the interaction between time and group on spatial abilities. In addition, no statistically significant difference was found between the academic performance of the experimental group and the control group and no significant difference was found in the weekly measurements of the groups. It was suggested that AR applications are very useful for students' spatial skills in technical drawing.