White spot lesions (WSLs) are early indicators of dental decay or demineralization, appearing as chalky white or opaque areas on tooth surfaces. These lesions signal a compromised enamel structure and can progress to severe tooth decay if untreated. Major causes include poor oral hygiene and high starch and sugar consumption, with the condition reflecting a dynamic balance between demineralization and remineralization. The process involves repeated acidic conditions that disrupt enamel (pH 5.5) and intermittent returns to neutral pH (7.0).WSLs, defined by Fejerskov and Kidd as the first visible sign of carious lesions on enamel, can be reversible if detected early. They often appear rough and porous compared to non-carious white spots, which are smooth and shiny. Accurate differentiation and early diagnosis are crucial for effective management.This book explores the epidemiology, etiology, diagnostic methods, prevention, and treatment of WSLs. It aims to enhance understanding and develop evidence-based strategies for their management.