This study examines the difference in effectiveness between two scientific inquiry programs-one with an emphasis on scientific reasoning and one without a scientific reasoning component-on students' scientific concepts, scientific concept-dependent reasoning, and scientific inquiry. A mixed-method approach was used in which 115 grade 5 students were administered the scientific concept test, scientific concept-dependent reasoning test, and scientific inquiry test before, 1 week after, and 8 weeks after instruction. In addition, students' scientific inquiry worksheets in the classroom were collected and evaluated. Results indicated that the experimental group outperformed the control group, regardless of scientific concept test, scientific concept-dependent reasoning test, and scientific inquiry test. Moreover, the classroom inquiry worksheets results demonstrated that the experimental group generated a significantly greater number of testable hypotheses, correct hypotheses, and correct evidence-based scientific explanations and a higher level of scientific reasoning than did the control group.