The purpose of this article is to present findings from a systematic analysis of elementary-school science textbooks. Comparisons of content domains and vocabulary are presented for the Merrill (1982) and Silver-Burdett (1985) science programs, grades 1–5 as well as the fourth-grade Holt (1980) and fifth-grade McGraw-Hill (1974) texts. Analyses of how each publisher presents information, types of questions, and various text characteristics reveal striking differences between programs. Systematic comparisons of content domains between programs also reveal few instances of “inconsiderate” texts. The textbooks analyzed were selected because they are used in the three school districts participating in our longitudinal study. Results are discussed in light of the differences found between programs regarding textbook content and opportunity to learn, the greater amounts of text and activities within each program, and teachers' probable uses of textbooks, the long-term results of students' exposure to various textbooks, and the need for careful examination of materials in order to determine their quality.