Urinary iodine was estimated chemically by the kinetic method, after mineralisation of the organic iodide by alkaline ashing. The experimental conditions were optimised. The methodological modifications of an existing technique are highlighted. Urinary iodine levels were determined in 349 school children of Bombay, of whom 163 had Grade IA/IB/II goitre and the remaining 186 did not have goitre. Urinary iodine concentration (Mean±SEM) of the control (n=186) and the goitre (n=163) groups were 76.47±4.97 and 71.09±6.23 μg/g creatinine respectively. The difference in the means was statistically not significant. Urinary iodine exhibited a log-normal distribution. It is concluded that the presence of goitre in the clinically euthyroid group of children was not caused by iodine deficiency.