Many school teachers suffer from stress and burnout, and perfectionism is a personality characteristic that has been associated with increased stress, maladaptive coping, and burnout. Recent findings, however, show that perfectionism has both positive and negative facets. To investigate how these facets are related to stress, coping, and burnout in teachers, a sample of 118 secondary school teachers completed multidimensional measures of perfectionism, stress appraisals, coping styles, and burnout. Multiple regression analyses showed that striving for perfection was positively related to challenge appraisals and active coping and inversely to threat/loss appraisals, avoidant coping, and burnout whereas negative reactions to imperfection were positively related to threat/loss appraisals, avoidant coping, and burnout and inversely to challenge appraisals and active coping. Perceived pressure to be perfect showed differential relationships depending on the source of pressure: Whereas pressure from students was positively related to loss appraisals and pressure from students' parents was positively related to burnout, pressure from colleagues was inversely related to threat appraisals and burnout. The findings suggest that striving for perfection and perceived pressure from colleagues do not contribute to stress and burnout in teachers, whereas negative reactions to imperfection and perceived pressure from students and students' parents may be contributing factors.