Research investigated classroom environment antecedent variables and student affective outcomes in Australian high schools. The Technology-Rich Outcomes-Focused Learning Environment Inventory (TROFLEI) was used to assess 10 classroom environment dimensions: student cohesiveness, teacher support, involvement, investigation, task orientation, cooperation, equity, differentiation, computer usage and young adult ethos. A sample of 4,146 high school students from Western Australia and Tasmania responded to the TROFLEI and three student outcome measures: attitude to the subject, attitude to computer use and academic efficacy. Confirmatory factor analysis using LISREL supported the 10 scale a priori structure of the instrument. Structural equation modeling using LISREL was used to test a postulated model involving antecedent variables, classroom environment and outcomes. The modeling indicated that: improving classroom environment has the potential to improve student outcomes, antecedents did not have any significant direct effect on outcomes, and academic efficacy mediated the effect of several classroom environment dimensions on attitude to subject and attitude to computer use.