The aim of the present study is to examine whether subjective well-being is predicted by self-oriented perfectionism and self-assessment. The self-oriented perfectionism scale, self-assessment scale and subjective well-being scale (SWB) were administrated to a sample of voluntary 272 eight-grade students from three secondary schools in Sultangazi, A°stanbul. The research data were analyzed by correlation and simultaneous regression analysis. In this research, Pearson correlation coefficient was utilized to determine the relationships between variables. Simultaneous regression analyses assessed the contributions of self-oriented perfectionism and self-assessment to adolescents’ subjective well-being (SWB). Self-oriented perfectionism and self-assessment correlated significantly with SWB. SWB correlated positively with these variables. Furthermore, self-oriented perfectionism correlated positively with self-assessment. The simultaneous regression analysis showed that self-oriented perfectionism and self-assessment are significant predictors of SWB. The regression model predicting SWB was significant. The variables accounted for 33% of the variance in SWB. The significance and limitations of the results are discussed. Key words: Subjective well-being, self-oriented perfectionism, self-assessment, simultaneous regression analysis.