Objective. To evaluate the effect of different desensitizing toothpastes and coffee staining on the discoloration rate of natural human tooth and composite materials. Materials and Methods. A total of 56 human teeth and 56 composite specimens were used. After initial color measurements were taken, specimens and teeth were exposed to simulated toothbrushing with six desensitizing toothpastes containing different active ingredients: stannous fluoride, strontium acetate, potassium citrate and hydroxyapatite, cetylpyridinium chloride, arginine, and novamin. Specimens were then exposed to coffee staining. Throughout the staining procedure, the storing solution was refreshed every day and the specimens were brushed with the tested toothpastes. Color measurements and changes were recorded at each stage and analyzed with one-way ANOVA, Dunnett tests, and paired sample t-test (p<0.05). Results. The largest color change was obtained with the stannous fluoride toothpaste after coffee staining for natural teeth (2.6 E00?) and composite specimens (3.1 E00?). Coffee staining resulted in significant changes for E00? values of all groups, except for natural teeth brushed with a novamin-based (p= 0.06) toothpaste. For composite specimens, only the stannous fluoride and cetylpyridinium chloride-based toothpastes resulted in significant color changes relative to the control group. L? and b? values were also increased after staining for all groups (p<0.05). Conclusions. Desensitizing toothpastes alone did not cause perceptible color changes; however, in combination with coffee staining, it tended to increased discoloration for both composites and natural teeth.