Aim of research - to study the iodine supply of the region according to the degree of urinary iodine excretion in the West region of the Republic of Kazakhstan. Of 6493 schoolchildren participating in the study of the frequency of goiter, random sampling was applied to select 884 children to determine UIC. To establish the excretion of inorganic iodine in a single portion of urine in the field, express diagnostics, the "Iodine test" kits (manufactured in Ukraine), was applied. The collection of urine for the determination of UIC was carried out in disposable cups, hermetically sealed with stoppers to prevent the entry of iodine vapors into the test samples. The test was carried out immediately after urine collection. The concentration of iodine in the urine was expressed in μg/l. The method is semiquantitative and makes it possible to distinguish urine samples with iodine content below 70, from 70 to 100, from 100 to 300 and above 300 μg/L. The obtained data on the study of UIC in schoolchildren in the West Kazakhstan showed that the proportion of children with optimal urinary excretion of iodine (100-300 μg/L) is 62.67% (95% CI: 59.48-65.86%). Indices ranging from 100 to 200 μg/L were detected in 27.15% (95% CI: 24.22-30.08%, more than 200 μg/L and up to 300 μg/L - in 35.52% (95% CI: 32.37-38.68%) of schoolchildren. UIC exceeds 300 μg/L - in 18.89% (95% CI: 16.31-21.47%) of schoolchildren. Concentration of iodine in the urine of more than 400 μg/L was determined in 1.81% (95% CI: 0.93-2.69%) of children. Low excretion rates of iodine, less than 70 μg/L, were detected in 2.83 % (95% CI: 1.74-3.92%) of schoolchildren, and from 70 μg/L to 100 μg/L - in 13.8 % (95% CI: 11.53-16.07%). Thus, in 62.67% (95% CI: 59.48-65.86%) there is an optimal allocation of iodine in the urine, it can be considered that iodine status of the population of West Kazakhstan is adequate. In West Kazakhstan, in the absence of iodine deficiency, a strained goiter endemia remains.The formation of goiter endemia in the region does not exclude the influence of other strumogenic factors, which need further study.