This study investigated eighth-grade science students' (13-14-year-olds) perceptions of their vocabulary knowledge, learning, and content achievement. Data sources included pre- and posttest of students' perceptions of vocabulary knowledge, students' perceptions of vocabulary and reading strategies surveys, and a content achievement test. Students' perceptions of vocabulary knowledge were compared before and after instruction to see whether students believed they gained knowledge and the ability to explain categories of technical science terms. Students' perceptions of vocabulary knowledge increased as a result of instruction. The participants had favorable views of the vocabulary and reading strategies implemented and believed the literacy approaches were important for their developing science knowledge. In addition, students' content achievement was compared to a national data set. Students in this study outperformed a national data set on all content knowledge items assessed. Students' perceptions of their knowledge and vocabulary and reading strategies were congruent with their content achievement. This study is one of the first to highlight the pivotal role students' perception of vocabulary knowledge and vocabulary and reading strategies plays in science content learning.