The study was proposed to investigate the effect of a technology-integrated guided inquiry-based learning (TGIBL) and guided inquiry (GIBL) approach on preservice mathematics teachers' (PSMTs') plane geometry learning. For this purpose, pre-posttest non-equivalent quasi-experimental design was used. A total of 116 PSMTs within three intact groups: Group1 (48) treated with TGIBL, Group2 (38) with GIBL and Group3 (30) in conventional approach. A two-tiered geometry diagnostic test and a geometry procedural knowledge test were used to collect the data and their reliability were KR20 = 0.87 and ICC = 0.88, respectively. The data were analyzed through a paired sample t-test and a one-way MANOVA. According to the findings, there is statistically significant difference between the groups, that is PSMTs taught with technology-integrated guided inquiry significantly outperformed than other groups. Therefore, the integration of technology and guided inquiry must be considered by teachers' educators as a pedagogical strategy to enhance the learning experience and knowledge retention among pre-service teachers at college of teachers' education.