Purpose: The aim of this study was to investigate the color stability of soft denture liners and the effectiveness of denture cleansers on soft denture liners colored by food colorants in different time periods. Materials and Methods: A plasticized acrylic resin soft liner (Viscogel) and a silicone-based soft liner (Mollosil) were used in this study. From each material 30 specimens (a total of 60 specimens) were prepared in a Teflon mold 15 mm in diameter and 3 mm thick. The prepared specimens were stored in distilled water for 24 hours at 37°C. Initial color measurements of the specimens were made using a small-area colorimeter. The specimens of the two soft liners were divided into three groups each containing 10 specimens. The specimens of the first, second, and third group were immersed for 14 hours (2 hours × 7 days) in 3% erythrosine, tartrazine, and sunset yellow food colorant solutions, respectively. Then the second color measurements were made. After the second measurements, the specimens of each group were divided into two subgroups (n = 5) and were immersed in denture cleansers (Fittydent and Curadent Weekly) for 8 hours, and the third measurements were made. At the end of these procedures, the weekly simulation period was completed. The fourth, fifth, and sixth color measurements were made at the end of the simulation periods for 1, 2, and 3 months, respectively. Color difference (ΔE) values were calculated, and the derived data were analyzed using repeated measures analysis of variance for three-way classification and Bonferroni multiple comparison tests (α = 0.05). Results: There were significant differences between soft liners and cleansers in terms of color change. Mollosil demonstrated mean discoloration values (ΔE) between 0.81 and 2.66, Viscogel showed ΔE between 1.26 and 12.83. Viscogel exhibited slightly greater color changes than Mollosil and the results showed significant differences (p < 0.001). There was no significant difference between the food colorants (p > 0.05). Denture cleansers showed significant differences (p < 0.001). Fittydent demonstrated lower ΔE values than Curadent. Conclusion: Silicone-based soft denture lining material seems to be more resistant to staining. With respect to denture cleansers, Fittydent was more effective than Curadent in this trial. Copyright © 2007 by The American College of Prosthodontists.