The aim of this study was to improve pre-service teachers' ability to infer cross-sections of geometric solids with Wolfram demonstrations and Mathematica in Analytic Geometry II course. The study was conducted with third year students studying Elementary Mathematics Education. In this study, the pre-test--post-test control group design was used. Both before and after the procedure, both groups were administered the Santa Barbara Solids Test (SBST) developed to measure their ability to mentally visualize the cross-section that results from the intersection of a cutting plane and a geometric solid. During the procedure, the participants in the control group were mainly asked to complete the graph drawings of geometric solids by just using plane cross-sections in paper-and-pencil format whereas those in the experimental group were supplemented with computer aided instruction in addition to these paper-and-pencil activities. In addition, the students in the experimental group were asked about their opinions on the procedure. The results showed a statistically significant increase in average achievement for both groups. On the other hand, this increase in the averages was significant for all the indices, and therefore for all problem types, of the experimental group SBST whereas it was significant only for the embedded orthogonal and embedded oblique items and for all problem types of the control group (p<0.05).