Knowing the fact that pediatricians prescribe different iron supplements for children suffering from anemia, it might be interesting to study the effect of common iron supplements products on dental caries. Therefore, the aim of this in vitro study was to study the effect of four iron supplements on the initiation of dental caries. Four products of iron supplements were used. These products were: (1) Fer-in-sol (Bristol Myers Squibb Company, New Jersey, USA), (2) Ferotonic (Ram Pharmaceutical, Amman, Jordan), (3) Feromin (Riyadh Pharma, Riyadh, KSA) and (4) Ferose (Spimaco Al Qassim Pharmaceutical Plant, Saudi Arabia). 120 extracted human teeth were distributed randomly into six groups (n=20). Four groups from the iron products, in addition to a positive and a negative control groups were considered. Mutants streptococci bacteria (6715) grown in Todd Hewitt Broth were used. Assessment of decalcification and cavitation by two examiners was done daily for 60 days. Results revealed that all iron supplements have cariostatic effect and delayed the initiation of the dental caries except Ferose product. The mean dates for decalcification varied, with lowest for the positive control (10 days) and the highest was for Feromin. Cavitation was initiated in two groups; the positive control and Ferose groups. The mean of the first day of cavitation was after 55 days. It is concluded that some iron-supplement products have cariostatic effect. It is advisable to ask pedestrians managing children suffering iron deficiency anemia to prescribe iron-supplement products for treatment of anemia and fighting dental caries.