The Peer-Led Team Learning (PLTL) and the Science Writing and Workshop Template (SWWT) are two active learning instructional approaches which combine writing, inquiry, collaboration, and reflection, elements which have been associated with critical thinking development. In this study, we used a quasi-experimental pretest–post-test design to investigate the impact of the implementation of these two approaches on the critical thinking skills of first-year chemistry students, measured using the California Critical Thinking Skills Test (CCTST). The results indicate that implementation of the PLTL and the SWWT instructional strategies led to significantly higher gains in critical thinking.