This study aimed to evaluate the effectiveness of Ankara University Prep.School program through the perspectives of instructors and students. To this end, CIPP evaluation model was utilized. 406 students attending the prep.school in the 2008-2009 academic year and 12 instructors participated in the study. Data were gathered through a self-reported student questionnaire and an interview schedule which was designed for the instructors. Besides, in order to obtain more detailed information about the prep.school, written documents were examined. While the data based on the questionnaire were analyzed through descriptive and inferential statistics, content analysis was carried out to analyze the qualitative data. MANOVA with Pillai’s Trace test was employed to investigate whether significant differences among dependent variables across independent variables existed. Results of the study indicated that the program at Ankara University Prep.School partially served for its purpose. The findings revealed that some improvements in the physical conditions, content, materials and assessment dimensions of the program were required to make the program more effective.