Canadian data from the 1998 Cross-National Survey on Health Behaviors in School-Aged Children were analyzed to examine the effects of school experiences on personal health (physical health, mental health, self-esteem, helplessness, and body image) and interpersonal relationships (number of close friends and making friends) among adolescents. Hierarchical linear models with students nested within schools highlighted that both physical and mental health and self-esteem declined among Canadian adolescents across grade levels (Grades 6-10). Canadian adolescents also showed substantially increasing concerns about their body image. No health concern was found about feeling helpless and interpersonal relationship. The most important school effects pertained to parent behaviors at the school level with child-parent relationship being important to physical and mental health and parental involvement being important to self-perception (self-esteem, helplessness, and body image) and interpersonal relationship. (Contains 8 tables.)