As all practitioners are aware, the prevalence and incidence of dental caries keep increasing constantly and therefore early diagnosis and cessation of further progression would greatly help in maintaining the sound tooth structure. One of the earliest signs of dental caries is a white spot lesion, which is mostly missed, and only treated when the condition worsens. WSL are areas of demineralized enamel that occur due to a prolonged period of retained microbial biofilms most commonly associated in patients with poor oral hygiene and fixed orthodontic appliances. If caught early and intervened, WSLs can be reversed. Therefore, the diagnosis and treatment of WSL are of outmost importance, and this chapter will explain in detail various methods of diagnosing WSLs, its treatment protocol with the significance of remineralization of the same.