The purpose of this study was to explore the effects of students' science learning in Content and Language Integrated Learning (CLIL) at one elementary school in Taiwan. This study investigated student perceptions of both the content and language achievement of science learning in CLIL. Data collection techniques included graphic organizers, individual interviews, students' self-assessment, and students' tests. Findings showed that CLIL helped enrich student vocabulary size, foster student science knowledge, and lead them to expect to learn other subjects in English. They also enjoyed the CLIL approach, but expressed limited knowledge about the school flower.