Goitre, that’s enlargement of thyroid gland, and cretins had been known inIndonesia for long time, especially in areas around active vulcanoes. In areaswhere goitre is prevalence, cretinism is also common. This paper studied goitreprevalence to estimate the magnitude of cretinism and developmental deficit dueto iodine deficiency. Data set from National Mapping Survey 1996/1998 were usedfor analyses. Data set from Evaluation on Intensified Iodine Deficiency ControlProject 2003 were also used for comparison in the changes of goitre and urinaryiodine concentration. Epidemiological modelling was construct to estimate cretinand developmental deficit due to iodine deficiency. Prevalence of goitre in areaswith endemic goitre were not changes after five years intensive control program.Median urinary iodine concentration changed quite significantly. Around 0.33% ofpeople living in endemic goitre area (TGR> 5.0%) were estimated to suffer fromcretin and 0.9% were suffering from milder developmental deficit. Around 0.33%of baby born in areas with endemic goitre were cretin and 0.099% were bornwith milder developmental deficit. The higher the goitre prevalence the more thenumber of cretin and milder development deficit de to iodine deficiency.