This study examined the relationship of perfectionism with measures of achievement and achievement motivation and mental health aspects of depression and self-esteem in high school students. Participants were 123 tenth- through twelfth-grade students. Results of multiple regression analyses indicated that students' personal standards were significant predictors of academic achievement. Students' personal standards also significantly predicted achievement motivation. Analyses of the relationship between perfectionism and depression and self-esteem found that as students' personal standards increased, their levels of depression decreased and self-esteem increased. Furthermore, when students experienced a discrepancy between their personal standards and actual performance, their depression levels increased and self-esteem decreased. © 2000 John Wiley & Sons, Inc.