The purpose of this study is to assess the anxiety connected with target language of the high school students learning Turkish as a foreign language. In this study, descriptive relational screening model was used. Two scales were used for collecting data. First scale was FLCAS-Foreign Language Classroom Anxiety Scale; it was developed by Horwitz et al. and its validity and reliability was done by Horwitz. Alpha reliability coefficient of this scale was 0.97. The second scale was FLAS - Foreign Language Attitude Scale; it was developed by Briem and its validity and reliability was done by Corbin and Chiachiere. The scale was translated into Turkish and alpha reliability coefficient of this scale was 0.88. The participants are 314 students (from 27 countries) learning Turkish in GIH High School in Kayseri-Turkey. 314 students' responses were studied. The data were analyzed using means, standard deviation, Pearson correlation analysis, regression, and Mann Whitney U test. The findings show that there are in a tight relationship the success of Turkish course with the students' foreign language anxiety and attitude. Students who fail have a negative higher evaluation score than successful students. In addition, students who fail have more total anxiety score than successful students (p<0.05).