A second-order in time finite-difference scheme using a modified predictor-corrector method is proposed for the numerical solution of the generalized Burgers-Fisher equation. The method introduced, which, in contrast to the classical predictor-corrector method is direct and uses updated values for the evaluation of the components of the unknown vector, is also analysed for stability. Its efficiency is tested for a singlekink wave by comparing experimental results with others selected from the available literature. Moreover, comparisons with the classical method and relevant analogous modified methods are given. Finally, the behaviour and physical meaning of the twokink wave arising from the collision of two single-kink waves are examined.2010 Mathematics subject classification: primary 35K57; secondary 35Q51, 65M06, 65Y10.