Counsellors need to be able to understand perfectionism in students, and the different forms that this perfectionism may take, in order to provide their students with the appropriate counselling services. This study investigated gender differences in perfectionism, and examined the relationship of perfectionism to general self-efficacy, life-satisfaction, academic achievement and satisfaction with academic achievement among a sample of 419 high school students (47.0% female, 53.0% male). Data were collected using five scales: (1) The Almost Perfect Scale--Revised (APS-R; Slaney, Rice, Mobley, Trippi, & Ashby, 2001); (2) the General Self-Efficacy Scale (GSES; Schwarzer & Jerusalem, 1995); (3) the Satisfaction With Life Scale (SWLS; Diener, Emmons, Larsen & Griffin, 1985); (4) a single item scale for measuring satisfaction with academic achievement; and (5) a demographic information form. Results indicated that females are significantly more perfectionist than males. Adaptive perfectionists had higher self-efficacy, satisfaction with life, academic achievement and satisfaction with academic achievement than did both maladaptive perfectionists and nonperfectionists. Furthermore, there were no significant differences between maladaptive perfectionists and nonperfectionists on any of these variables. This implies that prevention and intervention programs should be designed to enable high school students to set realistically high standards.