This paper describes a study of the effects of guided inquiry module instruction on undergraduate construction engineering students' understanding of course concepts and attitudes toward module instruction. Eighty-one students from two sections of the same Construction Materials engineering course participated in the study. Both sections received guided inquiry module instruction (treatment) for three of the six course topics. Participants completed pre- and posttests for each topic, exams (midterm and final), and a questionnaire to assess attitudes and perceptions. Results of the study show students perceived module instruction to be more effective than the traditional lecture. Students across both sections indicated that they participated more during module instruction and that this approach was more effective in encouraging participation and providing opportunities for discussion, activities, and teamwork. Additionally, students performed better on certain topic posttests under the treatment condition. This study contributes to the growing research on the effectiveness of active instructional approaches in engineering education to improve student learning gains. Future research should consider instructor teaching style and class composition in the design of experimental comparisons. DOI:10.1061/(ASCE)EI.1943-5541.0000117. (C) 2013 American Society of Civil Engineers.