This study aimed to evaluate the efficacy and complications of several bleaching methods in patients with discolored teeth after orthodontic treatment. This randomized clinical trial involved 60 volunteers (31 women, 29 men) aged 14 to 30 years, who finished fixed orthodontic therapy at least three months before the study commencement and complained of discoloration on upper front teeth. The subjects were divided into four groups by treatment. The patients in group 1 received home bleaching, whereas those in groups 2 to 4 underwent in-office bleaching using a diode laser, a plasma arc and no light source, respectively. Tooth color was measured at baseline, one hour after the end of the bleaching procedure, and one week later, and the color alteration between different stages was compared among the groups. The severity of tooth sensitivity and the occurrence of other post-treatment complications were recorded. The color change between baseline and one week after treatment was greatest in the home-bleaching and the laser-assisted bleaching groups, and lowest in the plasma-arc bleaching group, although the difference between the groups was not significant (p > 0.05). Tooth sensitivity over 24 hours after bleaching was lowest in subjects who had undergone laser-assisted bleaching and highest in those who had received in-office bleaching without light (p < 0.05). All methods were effective in managing tooth discoloration after orthodontic treatment. Home bleaching produced favorable color alteration. Amongst the in-office approaches, laser-assisted bleaching should be considered as the best option, as it produced effective results with lowest tooth sensitivity and over a shorter period of time.