This study was intended to examine the progress of the geometric reasoning skills of pre-service mathematics teachers (PSMTs) in the College of Teacher Education, Oromiya, Ethiopia. In the study, there were three different classes: EG1 (n=48), EG2 (n=38), and CG (n=30), where PSMTs in EG1 were treated with technology into guided inquiry-based learning (TGIBL), EG2 with guided inquiry-based learning (GIBL), and CG with a conventional learning approach. A geometric reasoning test was used to collect data. The data were analyzed using a one-way ANOVA and a paired sample t-test. The findings showed that the effect of using the GIBL model assisted by technology was higher when compared to the other two models. On the other hand, a paired t-test showed significant mean gains in reasoning skills in the TGIBL and GIBL approaches. Hence, technology must be integrated into teaching and learning geometry at CTEs to promote PSMTs’ geometric reasoning skills.