Medline and Embase electronic databases were searched.Papers published between 1996 and 2011 were initially identified by one reviewer, with 10% being independently reviewed by a second reviewer having predefined inclusion and exclusion criteria.Data abstraction was conducted independently and meta-analysis was not attempted because of the heterogeneity of the studies.Inclusion criteria were met by four papers relating to the acquisition and colonisation of the oral cariogenic bacteria and caries outcome in infants, 13 papers were considered in relation to identifying possible determinants of early childhood caries (ECC) during the first year of life.The review confirmed that factors occurring during the first year of life affect ECC experience. Despite heterogeneity, findings indicated maternal factors influence bacterial acquisition, whereas colonisation was mediated by oral health behaviour and practices and feeding habits.