This study investigated the effects of an affective curriculum on multiple dimensions of perfectionism among middle school (grades 6-8) gifted students. A quasi-experimental nonequivalent control group design was employed; all participants (N = 153) completed pre- and posttests of the Goals and Work Habits Survey. The experimental group received affective curriculum consisting of nine 45-50-minute lessons in a gifted classroom for 6 weeks. Among participants with moderate to high levels of unhealthy perfectionism, t-tests showed the experimental group reported lower scores on Concern over Mistakes than the control group. Results of paired t-tests further revealed significant decreases in Concern over Mistakes, Doubts about Actions, and Personal Standards among unhealthy perfectionists in the experimental group. Translating multidimensional perfectionism theory into classroom-based interventions was successful in helping students decrease self-critical evaluative tendencies; however, the study showed no evidence of enhancing healthy perfectionism. Future directions and recommendations are discussed. (Contains 5 tables.)