Molecular dynamics (MD) simulation studies of the mercury-water interface are presented. A slab of water molecules, about 25Åwide, confined by mercury phases, is investigated. A rigid water model and a flexible water model are used to describe the water-water interactions. Recently, we parameterized ab initio calculations on mercury-water clusters to describe the mercury-water potential. The liquid mercury phase is approximated as a rhombohedral lattice. The mercury-mercury interaction is modelled by a harmonic potential. Our results show a significant influence of the mercury phase on the structural and dynamic properties of the water phase. The structure of the interface is analysed in terms of density functions, radial distribution functions, orientation of the water molecules, potential drop, and hydrogen bonding characteristics.