Abrasive flow machining (AFM) process is used in a wide range of applications to deburr, polish, radius edges, remove recast layers, and produce compressive residual stresses on the surface. The aim of the present work is to study the effects of the different process parameters, such as machining time, concentration and mesh size of abrasive, as well as media flow speed ... etc. on the produced surface roughness. A mathematical model to evaluate surface roughness has been presented using experimental design. This model is can be used for the prediction of the surface roughness. Comparisons between experimental and theoretical results are also presented.