The purpose of this research is to examine secondary school students' positive and negative perfectionism as a predictor of career development. 487 students from five different secondary schools in a city located in Turkey's Eastern Mediterranean Region participated in this study. Positive and Negative Perfectionism Scale (PNPS) and Childhood Career Development Scale (CCDS) were used as data collection tools in the study. The results show that positive perfectionism was a predictor of career development total score with six dimensions (curiosity/exploration, information, key figures, time perspectives, planning and self-concept). No relationship was found between career development and locus of control as well as interests dimensions. There was also no relationship between negative perfectionism and career development and dimensions.