Abstract The present study examined the associations among perfectionism, defense styles, and depression in an Israeli community sample of young adults. This study involved a comparison of self-reports and informant ratings on all measures. A community sample of 210 pairs of same-sex best friends from Israel completed the Multidimensional Perfectionism Scale, the Defense Styles Questionnaire – 40, and a depression measure. Analyses confirmed that socially prescribed perfectionism is associated with depression, not only in terms of self-reports but also in terms of informant ratings. In addition, informant ratings revealed a link between other-oriented perfectionism and depression. Both self-reports and informant ratings also indicated that socially prescribed perfectionism is associated with immature defense styles and neurotic defense styles. Further simultaneous Structural Equation Modeling (SEM) analyses of self-reports and informant ratings showed that maladaptive defense styles mediate the link between socially prescribed perfectionism and depression. The practical and theoretical implications of these findings are discussed.