The purpose of this study is to investigate the effect of using the Geometer’s Sketchpad software on the academic achievement of students in mathematics among grade nine students of Bedele Secondary and preparatory school. The study utilized a quasi-experimental design using intact group of students from two classes in the indicated school. Two instruments were used to gather information:- the students’ mathematics achievement and attitudes/ perception of students toward learning Mathematics. A survey questionnaire was used to measure students’ perception on the usage of Geometer’s Sketchpad in the learning of Geometry and some other topics of mathematics. In the study, the experimental groups used Geometer’s Sketchpad-based topics and worksheets and for each student there is an access computer/plasma equipped with the Sketchpad software. The control group used only the textbooks and they were learnt by usual learning method. Both groups took the same pre-test and post-test. This study indicates that the result of experimental group had a significant mean difference compared to the control group on post-test. The use of Geometer’s Sketchpad in mathematics classroom has positive effect on the students’ mathematics achievement and attitude towards the learning of geometry and some mathematics topics.