Questions remain about how to best prepare students to be environmentally literate. Although Canada and U.S. share similarities in education systems, diversity in student population, and historical roots in formalizing environmental education, Canada is one of the top performing countries in international science assessments while U.S. matches average performing countries. This study examined the relationship of individual and school-related factors to environmental literacy by comparing students' performances in knowledge, awareness, attitudes, and behavior about environmental issues between U.S. and Canada using PISA 2006. Findings suggest that knowledge, awareness, attitudes, and behavior are inter-related, and development of certain domains of environmental literacy may be enhanced by classroom student investigations. Prior explanations for U.S. lower performance in environmental literacy cannot be attributed only to low socio-economic status and student diversity.