Dense(1-x)Pb(In1/2Nb1/2)O-3-xPbTiO(3) (PIN-PT) ceramics were synthesised by hot forging and thermal grain growth. (1-x)PIN-xPT phase diagram was investigated by X-ray diffraction and dielectric measurements. The morphotropic phase boundary zone was found to be between a rhombohedral phase region for low PT contents and a tetragonal phase region for high PT contents, i.e. in the 0.34-0.39x range. A mixture of tetragonal and probably monoclinic phases was observed for x = 0.37 at room temperature.