In this research, the effectiveness of a group guidance program in terms of assisting first year high school students to choose realistically their study field was examined.The research was carried out with 40 pupils who were randomly selected among the first year Özel Ferda Lisesi pupils, in Ankara, during the academic year 2001-2002.The subjects were separated to two groups: the experimental group which attended the group guidance program and the control group which did not. Both groups were tested before the guidance program was implemented and after.The program developed by the researcher, was mainly based on cognitive-behavioural approach with a substantial emphasis on informational and interactional techniques.The independent variable of the research was the group guidance program that was applied to the experimental group. The dependent variable of the study was students’ aptitude points.The program consisted of 12 sessions and it was administered every five days. Each session lasted for about 90 minutes. After the last session of the program, the student evaluation scale, which was developed by Kuzgun, was given to both the experimental and the control group members. In order to test this hypothesis thedependent-samples t-test was used.The results indicated that the experimental group members’ score both in the aptitude test become closer to their teachers rating after the group guidance program while the control group members score did not change from the first to the second application of the test.