In an application of contingency theory, data from 45 Arizona schools were analyzed to determine the relationships between three sets of independent variables (organizational structure, leadership style, and environmental characteristics) and the dependent variable (organizational effectiveness as perceived by principals and teachers). Contingency theory focuses on the internal adjustments of organizations seeking to modify procedures to cope with change. Using the school as the unit of analysis, responses to an adaptation of Motts Organizational Effectiveness Questionnaire were obtained from 45 principals and 364 teachers (selected through a 20 percent random sample of teachers at each school). The data analysis procedure involved constructing a full model that included all the independent variables and the one dependent variable, and applying multiple linear regression. Restricted models were then constructed by removing variable sets one at a time. To further refine the analysis of the environmental factors, a factor analysis was performed. Findings are presented in text and tables. Among the findings are: (1) the three sets of variables, taken together, are significantly related to perceived effectiveness, leadership style being the most powerful predictor; and (2) the more formalized the school's organizational structure, the greater the teacher's perception that the school was effective. (MLF)