The purpose of this study was to examine the effects of using Instructional Geometric Activities (IGA) designed based on Van Hiele Thinking levels on Ninth grade students’ achievement. The sample of study consists of 30 students (male and females). A total of 15 students were in the treatment group and 15 were in the control group. The treatment group was taught Geometry through the regular method supported by the (IGA), while the control group was taught Geometry through the regular method used in the school without (IGA). Previous knowledge test in the scientific material and students’ performance in the previous year were used to identify students’ initial levels of Geometric understanding. Both treatment and control group students’ achievement was measured by using achievement test developed by the researcher. Using the equation (Kuder-Richardson-20), the test raw score registers a reliability of 0.82. The analysis of the test using (ANCOVA) showed that significant differences between the mean scores of treatment group and the control group in terms of the dimensional achievement test as a whole and in each of its levels.