Early childhood caries is influenced by a combination of biological, behavioral, social, and environmental factors. At the biological level, cariogenic bacteria such as Streptococcus mutans, frequent sugar intake, poor enamel quality, and reduced saliva flow increased risk. Feeding habits like prolonged bottle use, nighttime breastfeeding, or frequent snacking on sugary foods provide constant fuel for bacteria. Caregiver practices and knowledge also play a major role-delayed toothbrushing, limited use of fluoride, and low priority given to dental visits contribute significantly. Socio-economic conditions such as poverty, low parental education, and lack of access to dental care or fluoridated water are among the strongest predictors, since they shape diet, hygiene routines, and service use. Cultural norms, community resources, and public policies further influence whether children receive preventive care and adopt healthy practices. In short, ECC is a multifactorial disease, with determinants ranging from bacteria and diet to family behaviors, socio-economic status, and broader environmental and policy contexts.