OBJECTIVE The purpose of this study was to evaluate novel iodinated methacrylate copolymers as X-ray opaque denture base resins. METHODS The synthesis of specific monomers and suspension copolymerization with methyl methacrylate to produce copolymer beads. The resulting beads were processed in an identical manner to standard PMMA to produce test-pieces for mechanical testing. RESULTS Samples prepared from beads containing 25 wt% of the iodinated copolymer exhibited an X-ray opacity equivalent to that exhibited by a similar thickness of aluminium. Furthermore, the appearance and mechanical properties were comparable to standard PMMA, while thermal stability proved superior. CONCLUSIONS These novel iodinated methacrylate monomers show promise not only as polymerizable additives to methyl methacrylate to produce an X-ray opaque denture base but also as thermally stable copolymerizable additives to other applications where X-ray opacity would be advantageous.