The aims of this study were to evaluate the effects of Er:YAG laser on surface morphology of dental restorative materials namely glass ionomer cement, composite resin, polyacid-modified composite resin, resin-modified glass ionomer cement and unfilled resin, and to ascertain the ablation threshold of these materials. Crater diameters, crater depths and crater volumes of the ablated sites were measured to assess the ablation characteristics of different restorative materials. The surface morphology changes varied from nil effect, to ablation, fusion, combustion, and various combinations of these. The ablation threshold of all materials was 40 mJ except Delton (60 mJ).