This paper deals with the numerical estimation of temperature distribution in a finite size sample during a laser heat treatment process. An implicit splitting finite-difference method is used to discretize the three-dimensional unsteady governing partial differential equation into sets of algebraic equations, amenable for the application of tridiagonal matrix algorithm. The moving laser beam is considered to have Gaussian distribution. The results indicated that the maximum temperatures are reached everywhere in the material almost after the same elapsed time. The effects of beam powers and material properties are examined on the temperature time response. © 1998 Technomic Publishing Co., Inc.