This study was designed to follow up whether or not the creativity of adolescents showed significant changes in the 9th and 12h grades and is a longitudinal study. Correlational screening model, which is one of the descriptive methods, was used in this study. The sample group consisted of a total of 145 (76 girls, 69 boys) adolescents who were attending Yozgat High School in the city center of Yozgat, Turkey in the 2014–2015 school year and were selected from the 9th grade by using random sampling method. When the sample group came to the 12th grade, the number of the adolescents decreased to 136 (72 girls, 64 boys). The analyses were made based on the data collected from 136 adolescents who were available in the 12th grade. General Information Form and Torrance Test of Creative Thinking (Figural Form A) were used as the data collection tool. In the data analysis, frequency from descriptive statistics, Paired-Samples T-Test for repeated measures and t-test for unrelated measures were applied. As a result of the study, it was found that the scores of the fluency scores and resistance to premature closure scores of the adolescents who participated in the study in the 9th grade significantly differed from their fluency scores and resistance to premature closure scores in the 12th grade, and this differentiation was in favor of the fluency and resistance to premature closure scores of the 9th grade. Their elaboration scores in the 9th grade differed statistically significantly from their elaboration scores in the 12th grade and this differentiation was in favor of their elaboration points in the 12th grade (p <.05). The scores of abstractness of the titles in the 9th grade were in favor of the scores of female adolescents and also the fluency scores of the participants in the 12th grade were in favor of male adolescents and this differed statistically based on gender (p <.05).