This study investigates changes in prospective teachers’ levels of geometric thinking and the development of their geometric discourses in the classification of quadrilaterals. To examine prospective teachers’ thinking about geometry, this study connects Sfard’s discursive framework to another, namely the van Hiele theory. Findings of the study reveal discursive similarities and differences in participants’ geometric discourses within the same van Hiele level, as well as changes in geometric discourse as a result of changes in levels of geometric thinking. The study also investigates the usefulness of a discursive framework in providing rich descriptions of prospective teachers’ thinking processes.