A coupled thermoelastic-plastic plane-strain finite element model is developed to study orthogonal cutting process with and without flank wear. The cutting process is simulated from the initial to the steady-state of cutting force and cutting temperature, by incrementally advancing the cutting tool forward. Automatic continuous remeshing is employed to achieve chip separation at the tool tip regime. The effect of the degree of the flank wear on the cutting forces and temperature fields is analyzed. With the flank wear increasing, the maximum cutting temperature values on the workpiece and cutting tool increase rapidly and the distribution of temperature changes greatly. The increase of tool flank wear produced slight increase in cutting forces but significant increase in thrust forces.