Acidizing, a very common stimulation process, is generally initiated when near wellbore formation damage causes a reduction in the productivity of an oil or gas reservoir. The ultimate goal of acidizing is to improve the near wellbore permeability and hence it is required that the permeability change due to the process be evaluated. Predictions of permeability alteration can be made before starting a project, and also, the altered permeability can be stated after the process. This paper describes a computer model that predicts the permeability alteration of an acidization process. A complete computer package is developed which consists of iterative optimizations and huge computations in order to simulate the permeability and porosity changes at each point during the process and, finally, to predict the post process permeability. As the optimization algorithm. a genetic algorithm which is somewhat more effective than the conventional ones, is used in the computer model. Thus a solution technique for a permeability prediction problem in acidizing is presented in this paper with all its uniqueness of type and effectiveness in practical applications.