Instructional written materials play important roles as teachers' agents in effective teaching practices. Worksheets are one of the most frequently used materials. In this exploratory study, the relationships between worksheet usage and science achievement in 32 countries were examined through the use of TIMSS and PIRLS data and multiple regression analysis. Based on two dimensions, five types of relationships among science achievement, worksheet usage, and other related variables are identified. The first dimension is whether the status of significance in the association of worksheets used as a basis and science achievement changes before and after controlling four teacher and school variables: schools' emphases on academic success, safety and orderliness of school, teachers' confidence in teaching science, and instructional engagement of students. The second dimension is the interaction of worksheets as a basis and classes' lack of readiness. The interaction between worksheets as a basis and reading achievement in science achievement is found to be not significantly different from zero in all participating countries. Four directions of further investigation are suggested based on the results.