This paper offers insight into teachers' perspectives on the role of manipulatives in the mathematics classroom on either side of the primary to post-primary transition (sixth class teachers in Irish primary schools and first year mathematics teachers in post-primary schools) to examine if discontinuities exist around their usage. The transition from primary to post-primary education is considered the most difficult of all educational transitions that students face, with negative effects more pronounced in the subject of mathematics. A questionnaire involving several open-ended questions was distributed to teachers teaching students in the final year of primary school and teachers teaching mathematics to students in the first year of post-primary education. Results of the qualitative data analysis reveal insights into teachers' perceptions of the benefits, supports and obstacles to manipulative use. It reveals that, in general, teachers on either side of the boundary crossing are in agreement regarding the perceived benefits of using manipulatives and also the potential factors that inhibit their usage. On the other hand, their opinions regarding the factors that support the use of manipulatives are more divergent.