This study aims at identifying the effects of the mind-mapping technique upon students' perceptions of inquiry-learning skills, academic achievement, and retention of knowledge. The study was carried out in the Science and Technology course. A quasi-experimental research design with a pre-test and post-test control group, which was selected from seventh graders, was used in this study. Sixty-four seventh graders participated in this study during the 2010-2011 academic year in Izmir, Turkey. The result of the study shows that there is a significant difference in favour of the experimental group over the control group regarding the academic achievement, scores of retention of learning, and perception of inquiry-learning skill scores, both on cognitive and affective levels.