The aim of this article is to examine the literature and review the risk factors and disparities contributing to early childhood caries (ECC), which is a major health problem among preschoolers in the United States of America. A search was conducted using MEDLINE, PubMed, Google Scholar, and the Cochrane Library databases and the key terms "early childhood caries", "baby bottle tooth decay", "nursing caries", "dental caries", and "access to dental care and disparities". ECC is a multifactorial disease with risk factors like biological, social, environmental, dietary and cultural determinants. Prevalence of ECC is highest among disadvantaged children living in poverty and in high-risk North American population groups such as, American Indians, Mexican Americans and in Hispanics. It is also found in families with less education and who have limited access to dental care services. This summarized review of early childhood caries will determine the need of future intervention programs focusing on the underserved and disadvantaged section of the population to prevent ECC.