The aim of this study was to determine the effect of different surface treatments on the flexural strength of four different ceramic specimens. The four ceramic systems investigated in this study were lithium disilicate reinforced, zirconium oxide reinforced, glass-infiltrated alumina reinforced, and feldspathic ceramic. For the first group, grinding burs, for the second group polishing kit and for the third group glazing procedures were applied for surface treatment. Surface roughness, mean fracture toughness, and a SEM were used to describe surface features. The surface treatments affected the flexural strength and surface roughness of the ceramic systems evaluated. © 2009 The American Ceramic Society.