The desire for perfect and white teeth can be accomplished in aesthetical dentistry by modern tooth bleaching methods. Within the scope of a clinical study, laser assisted in-office bleaching was applied to the teeth of 20 individual patients with a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (lambda = 1.064 microm, average power 4 W, pulse repetition rate 10 Hz, pulse duration 320 micros). The treatment was carried out in a split-mouth design, each patient having two appointments with 1 week in between. Laser activation of the bleaching agent was performed on teeth 14-11 and 34-31 per session, with a total irradiation time of 30 s per tooth. The initial and the final color of the teeth were ascertained by VITA Colorsticks and the dental chromatometer ShadeEye NCC. Whitening was detected in the laser-activated and in the non-activated quadrants. Statistical evaluation showed that the additional activation of the bleaching agent by the Nd:YAG laser had produced no significant influence on the whitening (P > 0.05). The results achieved in this study should be scrutinized critically. They give cause for one to reconsider the treatment conditions or the laser parameters used, or even to query the application of the Nd:YAG laser in general during in-office bleaching.