This mixed method study mainly explored how the extent of pre-service chemistry teachers' understanding of the particle nature of matter (PNM) affects their understanding of solution chemistry in the context of multirepresentational (MR) instruction. The ultimate goal was to describe the levels of understanding of specific solution chemistry concepts of a group of participants with a high understanding of the PNM and a group with a low understanding of the PNM before and immediately after MR instruction. Data sources included questionnaires about the PNM and interviews on solution chemistry. Data from these sources were coded and analyzed using quantitative and qualitative methods. There was a statistically significant difference between the results obtained for the understanding of solution chemistry before MR instruction for participants with a high understanding of the PNM and those with a low understanding of the PNM. Both groups of participants exhibited substantial progress towards the scientific understanding of solution chemistry from pre- to post-instruction; however, the participants with a high understanding of the PNM still outperformed those with a low understanding of the PNM in terms of developing a more scientific conceptual understanding of the topic after the MR instruction. Moreover, when the participants were provided with an opportunity to view dynamic visual particulate representations of phenomena to support verbal representations, about two-thirds of the participants from both groups were able to develop a scientific understanding of dissolution regardless of the extent of their understanding of the PNM. Yet, the findings suggested that the participants with a high understanding of the PNM were more likely to develop a scientific understanding of a particular concept (e.g., supersaturated solutions) in solution chemistry even without viewing the available visual particulate representations of the phenomenon.