A total of 2,034 subjects aged 15 years and above from different parts of the State of Kelantan were studied to determine goiter size and urinary iodine excretion. The State was divided into 2 areas - area 1 consisting of localities in the districts near the coast and area 2 consisting of localities in the inland districts. There were 1,050 subjects in area 1 and 984 subjects in areas 2. The mean age (+/- SE) of subjects in areas 1 and 2 were 38.2 + 0.5 and 37.1 +/- 0.5 years, respectively. The prevalence of goiter was 31.4% in area 1 and 45.0% in area 2; the difference was statistically significant (p < 0.05). However, the prevalence of large and visible goiters (grades II and III) was only 2.0% in area 1 and 3.3% in area 2; the difference was not statistically significant. The mean (+/- SD) urinary iodine excretion in areas 1 and 2 was 57.1 +/- 2.1 and 56.8 +/- 2.1 micrograms I/g Cr, respectively. The values were below those recommended by WHO. There was no significant difference in urinary iodine excretion between those with and without goiters in both areas and also between the grades of goiters. There were significantly more females with goiters than males in both areas but there was no significant difference in the urinary iodine excretion between the 2 sexes. Thus based on urinary iodine excretion, the iodine intake of the population in this area, was suboptimal and this was associated with a high prevalence of goiter.