In this study, we looked at the impact of our specially designed inquiry-based science courses for pre-service elementary teachers on their science content knowledge as measured by a high-stakes state certification test for elementary education. We conducted a pre/post-analysis of the certification test scores of 1,003 pre-service teachers. Cohort 1 consisted of 424 students who took the test prior to implementation of our reformed science courses. Cohort 2 consisted of 579 students taking the test after complete implementation. We examined overall test scores, science subscores, total science credits, age, and science transfer credits. We found that the overall test score dropped significantly from cohort 1 to cohort 2, but the science subscores remained unchanged. Our results showed that students who took all 3 of the science content courses vs. none scored significantly higher on the science portion, non-traditional students (older than 25) scored similarly to traditional-aged students, and there was a negative correlation with the number of science courses transferred. Of importance is the fact that students who took the minimal number of science courses and are less interested in science passed the science portion at the same rate (over 90%) as science majors and minors. We conclude that our pre-service elementary teachers can and do learn science content using inquiry as recommended by the National Science Education Standards (NRC, 1996).