Iodinated and/or brominated derivatives of aromatic dihydroxy monomers are prepared and polymerized to form radio-opaque polymers. The monomers may also be copolymerized with other dihydroxy monomers. The iodinated and brominated aromatic dihydroxy monomers can be employed as radio-opacifying, biocompatible non-toxic additives for other polymeric biomaterials. Radio-opaque medical implants and drug delivery devices for implantation prepared from the polymers of the present invention are also disclosed.