Subject and aim:The aim of this study was to evaluate the efficiency of diode laser-activated bleaching systems for color change of teeth. Materials& Methods: 40 premolars with intact enamel surfaces were selected for five external bleaching protocols (n=8). Two different wavelengths of diode laser (810 and 980 nm) with two different hydrogen peroxide concentrations (30% and 46%) were selected for laser bleaching. Group 1 received bleaching (Heydent-Germany) with a 810 nm diode laser; Group 2 received bleaching (Heydent-Germany) with a 980 nm diode laser; Group 3 received bleaching (laser white*20-Biolase) with a 810 nm diode laser; Group 4 received bleaching (laser white*20-Biolase) with a 980 nm diode laser, with an output power of 1.5 W, in continuous wave (cw) mode for each irradiation. Group 5 as control group received 40% hydrogen peroxide (Opalescence Boost, Ultradent-USA) with no light activation. The color of teeth was scored at baseline and 1 week after bleaching with spectrophotometer. Color change data on the CIEL*a*b* system were analyzed statistically by the one-way ANOVA and Tukey's HSD test. Results: All the bleaching techniques resulted in shade change. According to DE values, all techniques were effective to bleach the teeth (DE ≥ 3). Statistically significant differences were detected among bleaching protocols (p=0.06). Regarding shade change values expressed asDL*, Da*, Db*, DE*, laser bleached groups were no statistically different with each other (p>0.05). Conclusion: Bleaching with different wavelengths of diode laser resulted in the same results.