A total of 120 Sprague-Dawley rats were divided into 3 groups. Group A was born to normal mothers (NM) and suckled on iron deficient anemic mothers (AM) until 21 days of age. This group was subdivided into Group A1 fed an iron deficient diet until 49 days of age and then given IM iron plus an iron sufficient diet (ISD) and Group A2 given IM iron plus ISD from 21 days. Group B was born to AM and suckled on NM and thereafter fed an ISD and Group C, born to and suckled on NM and thereafter fed on ISD. At birth pups of AM (Group B) had significantly lower body weight, hemoglobin (Hb); brain DNA; spleen weight, DNA, protein and iron compared to pups of NM (Group C). At 21 days, Group A2 had significantly lower body weight, Hb, serum iron, brain weight and iron; liver weight, DNA, RNA, protein and iron; spleen weight, DNA, RNA, protein and iron; kidney weight, RNA and iron compared to Group C. There was no significant difference between Group B and C. At 49 days, Group A1 had significantly lower body weight, Hb; serum iron; brain weight, DNA and iron; liver weight, DNA, RNA, protein and iron; spleen RNA and iron; kidney weight, DNA, RNA, protein and iron compared to Group C. At 102 days, no significant differences were observed in any parameters in all groups. Iron deficiency in rats in utero and during weaning periods results in significant cellular changes in brain, liver, spleen and kidney which are corrected by iron administration.