This study aims to investigate the relationship between multidimensional perfectionism in predicting career decision making self- efficacy among high school seniors. The sample of the study consisted of 302 students from three different schools in Trabzon city center, Akcaabat and Yomra disctricts (General High School, Anatolian High School and Science High School). The distrubution of students by gender is in the form of 139 girls (46%) and 163 boys (64%). A demographic data form prepared by the researcher, Career Decision Making Self- Efficacy Scale and Multidimensinal Perfectionsim Scale were used to collect the data. Pearson correlation coefficient and multiple regression analysis were used to analyze the data. Findings of this study showed that, multidimensional perfectionism' subdimensions "Organization" and "Personal Standarts" were found to be significant predictors of career decision making selfefficacy in significant levels among senior high school students. These results were discussed in light of relevant literature and some new direction were given to the further studies.