The aim of this study is to investigate the question: ``Does the use of a Geometer's Sketchpad help secondary students to improve their geometry performance?'' The respondents were students enrolled in a high school (grade~7) in a northern suburb of Athens. The experimental group consisted of approximately 40 students, who spent at least one hour per week doing computer explorations for the first six weeks of the last semester. There were 39 students in the control group, which was not exposed to the computer explorations. Students in both groups were pre-tested and post-tested for their geometry performance. The results of the study indicated that the use of technology is needed for students to make significant progress in geometry.