A new general non-isothermal theological model of metal alloys in the thixoforming processes has been derived. The model uses the two-phase approach to flow description with two momentum conservation equations buckled by common pressure and interface drag force. The thixotropy phenomena occurring in the globular structure of the alloy, is modelled by means of an extra kinetic equation describing agglomeration degree. The non-isothermal processes are governed by the thermal energy conservation equation coupled with a temperature-enthalpy and solid fraction relationship. The time evolution of the solid fraction is described by the mass conservation equation for the solid phase with a source term based on the Sheil equation. The mathematical model has been implemented in an original efficient finite element algorithm, which is tested against very well known benchmark problems as well as used in a real 3-D simulation of a thixoforming process. (C) 2003 Elsevier Ltd. All rights reserved.