International comparisons in educational research can be difficult to accomplish because the findings of individual countries may not be comparable due to study design or inherent country features that cannot be manipulated. Quantitative meta-analysis techniques have great potential in improving international comparisons. In this paper, participant countries/regions in an international study were treated as study populations, and meta-analytic techniques were used to synthesize study outcomes across countries. Homogeneity tests were conducted to determine whether there was a common population parameter across countries, outliers were identified empirically, moderator effects die to country characteristics were studied, and homogeneous country outcomes were combined by a variance-weighting method to yield an optimal parameter estimate. The study of interest in this paper was gender differences in students' perceptions about whether girls or boys will do better in mathematics. Data are a subset of data from the Third International Mathematics and Science Study (TIMSS), in which seventh- and eighth-graders from 25 countries participated. Multiple regression models were used to country-level analyses, and effect sizes were computed. Overall, the meta-analytic techniques were satisfactory in analyzing the TIMSS data, illustrating the potential of meta analysis in improving the validity of international comparison studies. Meta analysis appears to be capable of detecting substantial differences in country outcomes and effective in offering strategies to deal with the situation. Appendixes present tables of coding schemes and outcomes of moderators, independent variables and questionnaire items, and a summary of meta analytic results. (Contains 7 tables, 8 figures, and 20 references.) (SLD)