The aim of this study is to analyze the relations between perfectionism and negative automatic thoughts of teacher candidates. The participants of the study are composed of 243 teacher candidates who still continue their education in their 1., 2., 3., 4. grade in the School Teaching Programme of the Faculty of Education of Recep Tayyip Erdogan University in the academic year of 2011-2012 in Turkey. In order to determine the perfectionism feature of the teacher candidates "Positive and Negative Perfectionism Scale" is used and in order to determine their negative automatic thoughts "Automatic Thoughts Scale" is used. In the analysis of the data obtained, Pearson moments multiplication correlation coefficient is calculated and Structural Equation Modelling is practiced. In the consequence of the research, it is seen that positive perfectionism thoughts of teacher candidates affect negative automatic thoughts significantly in a negative way. In addition to that, it is seen that negative perfectionism features of the teacher candidates affect negative automatic thoughts in a positive way. In the light of these consequences, some suggestions have been made for this practice and for the researches to be conducted in the future.