This study investigates the influence of inquiry-based laboratory activities on the understanding of heat concepts and the self-efficacy beliefs of pre-service primary teachers. Recognizing that both scientific literacy and teaching efficacy are critical for effective science education, this research aims to determine how inquiry-based laboratory tasks can enhance these attributes. The study involved 39 pre-service teachers participating in a sequence of eight three-hour courses. Assessments of conceptual understanding and self-efficacy beliefs were conducted before and after the intervention. The results indicate significant improvements in both areas, suggesting that hands-on, inquiry-based learning can effectively enhance scientific understanding and teaching confidence. These findings underscore the importance of integrating such methodologies into programs for teacher education to prepare future educators for fostering scientific literacy in their students.