In this study, a 2(3) full factorial design methodology was applied to study the effect of three process input variables, namely ash content (30 and 50 wt%), pressing pressure (120 and 150 MPa) and heat treatment temperature (900 and 1050 degrees C) on the characteristics of ceramics. The ceramics specimens were prepared from oil shale ash and waste glass by pressing followed by heat treatment. The oil shale was obtained from El-Lajjun region in Jordan. Three response variables were chosen to investigate the process variables of interest. The response variables were water absorption, chemical absorption and bending strength. It was found that higher heat treatment temperatures are favored to obtain ceramics with lower water absorption, lower chemical absorption and higher bending strength. The main effects of ash content and pressing pressure on the characteristics of ceramics were found to be shared by interaction effects. The factorial design methodology revealed the interaction and its effect among process input variables on the characteristics of ceramics. Ceramics with minimum water absorption (7.7%), minimum chemical absorption (9%) and bending strength (41 MPa) were obtained based on the following optimized conditions: 30 wt% ash content, 120 MPa pressing pressure and 1050 degrees C heat treatment temperature.