Iron deficiency anemia (IDA) affects human quality of life impaired learning process, working abilities and natural resistance. This impairment is irreversible in some age group although iron status becomes normal. The prevalence data of IDA among young children is rare in most developing countries and different from country to country due to nutrition, child rearing pattern and genetic background. There is a mixtures of hemoglobinopathy genes in Southern Thailand so solving of IDA problem in Southern Thailand suspected to be a complex situation. How big the IDA problem in young children in Southern Thailand is not know and the natural nature of the population due to hemoglobinopathies involve in solving the problem. The special study of the nature and predictors of anemia is needed for proper policy formulation of this public health problem in southern Thailand. A community study was designed to establish the prevalence and predictors of iron deficiency anemia in the pre-school rural children of Krabi province in Southern Thailand. Participants aged 1-4 years were selected by two–stage cluster random sampling , firstly random sampling the villages until get 30 villages and secondly random sampling ten participants from all children of each selected village.Children with history of chronic illness, malaria, prematurity, blood dyscrasias , acute illness and/or cured less than 2 weeks, iron supplement therapy with or without past blood transfusion during last 3 months and second to third degree malnutrition were all excluded. Three hundreds children between ages 1-4 years were identified belonging to this population. All participants should had their consent forms signed by parents to participate in this survey before the study activities started. Venous blood was measured for levels of hemoglobin and serum ferritin. Stool was collected to perform occult blood test for silent GI bleeding identification and Kato’s thick smear for hookworm ova identification. All of them had a full blood count, serum ferritin, hookworm ova and occult blood estimation performed. Data of sociodemographic characteristics (income, religion, parents’ education andoccupation) and child rearing was interviewed. Results: 28% of the sample are anemic (hemoglobin less than 11 gm/dl). The prevalence was highest among 2 years old children. Male among aged 1-3 years is found more anemic than girl. The anemic prevalence reduced when children grew up. The severity of anemia is moderate. Iron deficiency (serum ferritin less than 12 microgram/L) was found in 24.3% of this population, 53.6% of anemic children were (IDA), 46.4% were non IDA. Mean hemoglobin of the anemic children is 9.3 ( 1.3 gm./dl. The prevalence of IDA was significantly lower when the children ages increased (p = 0.006 ). There is no significant difference between both sexes. Muslim children had significantly higher IDA than Buddhist children ( p = 0.001 ). Hookworm and silent bleeding were not the IDA causes among this group ( Odds ratio 1.995% CI = 0.0 - 21.6 ). This study is a new study of IDA prevalence among young children in Southern Thailand. Its finding confirmed that anemia and IDA is a public health problem among pre-school rural children in Southern Thailand. No need to set hookworm prevention program to prevent IDA in this young group because it is rare. There is 46.4% of non IDA anemia which should further study before setting policy formulation of anemia among this population group in Southern Thailand.