Abstract: This invention relates to a method for bleaching teeth that have been discoloured by a staining agent. The method comprises the steps of coating an area of at least one tooth to be bleached with a dental bleaching composition and irradiating the coated area with laser energy for a predetermined period of time to activate an oxidising agent contained in the bleaching composition, the activated oxidising agent being capable of reacting with the staining agent to at least partly discolour the staining agent. In the method of this invention use is made of a laser emitting laser energy of a wave length capable of inducing a photochemical generation of radicals of the oxidising agent, which radicals in turn are capable of reacting with the staining agent to form a compound that is free of a conjugated electron system capable of absorbing visible light.