This paper draws on the Western Australian School Effectiveness Study (WASES) to examine school-level factors associated with improved teacher morale as one measure of effective high schools. The 1997 WASES teacher sample included 212 teachers from 28 rural and urban high schools in Western Australia. Data analysis using the Multilevel Linear Model focused on teacher responses to the School Level Environment Questionnaire (SLEQ), which includes eight subscales measuring relationship, personal, and system aspects of the school environment; measures of general self-concept and academic self-concept (teacher efficacy); and the teacher morale scale of the School Organizational Health Questionnaire. Teacher morale varied both within and between schools. Teacher morale appeared to be a useful indicator of healthy and effective schools, with a reasonable correlation with SLEQ scales. Differences in teacher morale, both across and within schools, were explained by six SLEQ scales: teacher affiliation, professional interest, mission consensus, empowerment, innovation, and work pressure. Teacher self-concept, both general and academic, had little effect on teacher morale, suggesting that morale was influenced by outside factors. (Contains 58 references and 6 data tables.) (SV)