The Third International Mathematics and Science Study represents the most comprehensive international assessment of educational contexts and student achievement yet conducted. As part of the examination of the effects of contextual factors on student achievement, a model was constructed that considered the effects of variables such as instructional practices, classroom environment, family expectations and resources, and student self-beliefs. This study was intended to examine cross-cultural variations in the relationships between instructional strategies and science achievement. For this study, students from three countries (Japan, Hong Kong, and Chinese Taipei) where relatively high levels of science achievement have been noted were examined. In addition, this study was designed to extend the results of previous research by (a) simultaneously examining the effects of several instructional strategies on science achievement and (b) assessing those relationships for students from three countries who were part of large national samples in a comprehensive international assessment of educational contexts and achievement outcomes. The findings from this study identify several classroom instructional strategies that were significantly related to science achievement test scores for students in three countries where relatively high levels of science achievement have been reported. Many of the findings were consistent with the results of programs and practices designed to improve student achievement in science. Finally, these results extend previous research findings by simultaneously assessing the effects of several teaching strategies on achievement and by examining students in cross-cultural settings as part of a comprehensive international assessment.