The successful preparation of single-phase Hg-doped (2223) using a nitrate decomposition/solid state reaction method is described in this paper. The effects of Hg doping on the formation of single-phase (2223) have been investigated by X-ray and synchrotron radiation diffraction. When compared with Pb-doped system, the use of Hg as a dopant has resulted in the reduction of both the final sintering temperature and the annealing time of the single-pure (2223) material, without any obvious deterioration of the superconducting properties.