A new surface based on poly(vinylferrocenium) (PVF(+))-modified platinum electrode was developed for determination of Hg(2+) ions in aqueous solutions. The polymer was electrodeposited on platinum electrode by constant potential electrolysis as PVF(+)ClO(4)(-). Cl(-) ions were then attached to the polymer matrix by anion exchange and the modified electrode was dipped into Hg(2+) solution. Hg(2+) was preconcentrated at the polymer matrix by adsorption and also complexation reaction with Cl(-). Detection of Hg(2+) was carried out by differential pulse anodic stripping voltammetry (DPASV) after reduction of Hg(2+). Mercury ions as low as 5 x 10(-10)M could be detected with the prepared electrode and the relative standard deviation was calculated as 6.35% at 1 x 10(-6)M concentration (n=6). Interferences of Ag(+), Pb(2+) and Fe(3+) ions were also studied at two different concentration ratios with respect to Hg(2+). The developed electrode was applied to the determination of Hg(2+) in water samples.