This study was conducted to identify the most salient organizational and personality factors contributing to burnout for elementary, intermediate, and secondary teachers; and to determine the pattern of causal predominance linking these stressors to burnout for each teacher group. Participants in the study, full-time elementary (N=599), intermediate (N=203), and (N=715) secondary teachers, responded to a series of questionnaires including the Maslach Burnout Inventory. An hypothesized model of burnout, based on replicated findings from the literature, was tested separately for each group of teachers using the analysis of covariance structures. Findings were consistent across groups in revealing the potency of role conflict, work overload, classroom climate, decision-making, and peer support as the primary organizational determinants of teacher burnout. Findings also emphasized the key positions held by self-esteem and external locus of control as important mediators of teacher burnout. Findings related to causal structure among the emotional exhaustion, depersonalization, and personal accomplishment facets of burnout make it clear that interpretation of burnout as a unidimensional construct is not meaningful. (LL)