Owing to their potential impact on students' cognitive and noncognitive outcomes, the negative attitudes toward science held by many elementary teachers are a critical issue that needs to be addressed. This study focuses on the science education of preservice elementary teachers with the goal of improving their attitudes "before" they begin their professional lives as classroom teachers. Specifically, this study builds on a small body of research to examine whether exposure to inquiry-based science content courses that actively involve students in the collaborative process of learning and discovery can promote a positive change in attitudes toward science across several different dimensions. To examine this issue, surveys and administrative data were collected from over 200 students enrolled in the "Hands on Science" (HoS) program for preservice teachers at the University of Texas at Austin, as well as more than 200 students in a comparison group enrolled in traditional lecture-style classes. Quantitative analyses reveal that after participating in HoS courses, preservice teachers significantly increased their scores on scales measuring confidence, enjoyment, anxiety, and perceptions of relevance, while those in the comparison group experienced a decline in favorable attitudes to science. These patterns offer empirical support for the attitudinal benefits of inquiry-based instruction and have implications for the future learning opportunities available to students at all education levels.