A preliminary survey of 32 school districts identified as having highly developed teacher evaluation systems was followed by the selection of 4 case study districts (Salt Lake City, Utah; Lake Washington, Washington; Greenwich, Connecticut; and Toledo, Ohio) representing diverse teacher evaluation processes and organizational environments. Common factors found to underlie the success of the evaluation systems in each case study district were: demonstration of organizational commitment to teacher evaluation, procedures for ensuring evaluator competence, collaboration with the teachers' organization and individual teachers, and compatibility of teacher evaluation with other district management strategies. The conclusions reached, to be modified on the basis of local experiences, are that a successful teacher evaluation system should: (1) suit the educational goals, management style, conception of teaching, and community values of the school district; (2) have top-level commitment to, and resources for, evaluation; (3) match the purpose of the district; (4) have efficient use of resources to achieve reliability, validity, and cost-effectiveness; and (5) have teacher involvement and responsibility. (MLF)