laser drilling play an important role in special applications with high accuracy dimensions, this paper was focused on two types of ceramics; aluminum oxide (Al2O3) and zinc oxide (ZnO) of 4 mm thick have been drilled by using continuous wave (CW) CO2 laser. the exposure times applied were (20, 40, 50) sec and the other laser parameters were kept constant and to avoid large distortion, A comparison between the two kinds of ceramic are carried out to determine the effect of laser parameters on them. It founds that ZnO holes are cleaner than Al2O3 holes. Experiments proved that Exposure time at 50 sec resulting in similar penetration depth of 1.5 mm for both materials. Also for exposure time 41 sec gives the same taper angle.