The teeth are an integral part of facial aesthetics and are involved in a complex social, cultural and psychological interaction. Discolouration of tooth is a common aesthetic problem caused by either intrinsic or extrinsic factor. For people with severe discolourations, bleaching can be an important and valuable treatment. In-office bleaching is one of the most requested procedures in many dental offices, a great way to get a fast and immediate change in the colour of their teeth. The normal colour of such a tooth can be restored by decolourizing the stain with a powerful oxidizing agent such as 35% hydrogen peroxide which is directly placed on the labial surfaces of the tooth to be treated.The bleaching agent is commercially available in the form of a gel.These case reports reflect the remarkable change of tooth colour by in-office bleaching. Key Words : Bleaching agents; Fluorosis; Hydrogen peroxide.