The purpose of this study was to determine the staining potential of glass-ionomer and composite resin restorative materials following immersion in common beverages. Nine tooth-colored restorative materials were used: three glass ionomers (ceramic- reinforced, resin-modified, and conventional) and six composite resins (nanofilled, ormocer-based, flowable ormocer-based, polyacid-modified, microhybrid, and flowable microhybrid). Disk-shaped specimens were prepared and immersed in 37°C distilled water for 24 hours. Over a 2- week period, five specimens of each material were immersed daily in one of three test beverages (coffee, tea, or cola), then stored in distilled water. A control group of five specimens of each material was continuously immersed in distilled water during the test period. Color coefficients (CIELab) were measured by a spectrophotometer before and after staining. All materials were susceptible to staining by all test beverages, while distilled water caused no perceptible color change. As determined by ANOVA and Bonferroni tests, there were highly significant differences in the change in color (ΔE) for tested materials in different beverages (P = .001). The ΔE was significantly higher for coffee and tea than for cola; the ΔE was significantly higher for the polyacid-modified composite resin than for all other materials. The material with the least amount of color change in coffee and tea was the ceramic-reinforced glass ionomer (ΔE = 12.45 and 10.64, respectively) and in cola was the nanofilled composite resin (ΔE = 1.93).