Abstract Four studies are reported on the structure of environmental attitudes. Based on Stern & Dietz' (1994) value-basis theory for environmental attitudes, we predicted that concerns for environmental issues would form three correlated factors. The first study presents the results from a confirmatory factor analysis of the proposed three-factor model among a sample of 1010 U.S. college students. The second study presents the results from a telephone survey of 1005 U.S. respondents. The third study examines the relationship between the three identified types of environmental concerns, existing measures of environmental attitudes, empathy, and social-value orientation. The final study presents the results from a multi-group confirmatory factor analysis examining the factor structure of environmental concerns among college students in ten countries. Additional analyses are provided on the relationship between values and environmental concerns. Taken together, the results provide strong evidence for the distinction between egoistic, altruistic, and biospheric environmental concerns.