Identification of the association between Early Childhood Caries (ECC) and Iron Deficiency Anemia (IDA) will aid pediatricians and pediatric dentists to enhance health promotion measures to reduce the related morbidity in children. This systematic review aims to determine an evidence based association between ECC and IDA. A systematic search was carried out from MEDLINE via PubMed, EMBASE, LILACS, Cochrane Oral Health Group’s Specialised Register, CINAHL via EBSCO, Web of Science and Scopus up to May 2020. Hand searching and grey literature screening were also conducted. Cross-sectional, case-control and cohort studies in English language which assessed the association was included. Two reviewers independently assessed the study quality and extracted the outcome data. A total of 1434 studies were identified. Fourteen studies qualified for qualitative review and seven of them for a meta-analysis. In comparison with children not affected by ECC, those affected had an increased likelihood of IDA (OR = 6.07 (3.61, 10.21). The meta- analysis showed no statistical difference when comparing blood parameters (Hb, MCV and Serum ferritin) in children with and without ECC. This systematic review demonstrates an association between ECC and increased odds of IDA rather than it being the cause for IDA. Further longitudinal studies with robust methodology are required to determine an evidence based association.