To determine the types of various dental restorative materials used, and the reasons for the placement and replacement of dental restorations in 10 randomly selected polyclinics in Riyadh, Saudi Arabia.A cross-sectional descriptive study.Ten selected polyclinics in Riyadh metropolitan area, Saudi Arabia during a period of two weeks in January 2003.Information was collected by using a specially-designed form that was distributed to one dentist in each selected polyclinic. The dentists were asked to record specific details for all restorations placed in adult patients. Chi-square tests were used to analyze the data.Data were collected for 326 restorations. Amalgam (52.5%) was the most commonly used restorative material followed by resin composite (31.3%) and temporary restorations (14.4%), with a minimal use of glass ionomer cement (1.8%, p<0.001). Most of the restorations (69.9%) were initial placements, while 30.1% were replacement restorations, (p<0.05). Caries was the major reason for the initial placement (92.1%), and for the subsequent replacement (96.9%) of restorations.Amalgam and resin composite were the most commonly used restorative materials. Caries was the major reason for the initial restoration placements and subsequent replacements.