This paper is concerned with the importance of testing and developing integrated multilevel educational effectiveness models through comparative studies in educational effectiveness. It is argued that secondary analyses of international comparative studies could help researchers test and develop integrated multilevel educational effectiveness models. To support this argument, a secondary analysis of TIMSS 1999 data was conducted in order to provide empirical support to the comprehensive model of educational effectiveness. A secondary aim of this analysis was to shed light on the value of the results that can be obtained from comparative studies in educational effectiveness. The methods used to conduct the secondary analysis and its main results are presented. Finally, the implications of the findings for the development of a theoretical framework of educational effectiveness research are drawn. (Contains 1 table.)