The issues that prompt this study are based on current research indicating the positive effects of inquiry learning on the cognitive development of children. The purpose of this case study was to understand the effects of inquiry learning on the academic achievement and bilingual verbal cognition of 5th grade bilingual students in a French/English dual immersion program. The treatment group of students completed research projects through a guided inquiry learning approach, while the control group experienced the traditional problem-solving research approach. Empirical findings reported a significant mean increase in mathematics achievement, bilingual verbal cognitive ability, higher motivation to learn and increased self-efficacy in the treatment versus the control group of students.