Résumé : The 'Thyromobile' project was initiated to update information on iodine supply in schoolchildren aged 6-14 years in Europe. It involved 4 places in France: Lorraine, Rhone-Alpes, Languedoc-Roussillon, Midi-Pyrenees, Schools of the three former places had been investigated in 1986 during the Mornex's study whereas in the latter they had never been investigated in the past. With a mobile unit, all children (n = 1522) had a thyroid echography performed by the same trained investigator, and urinary iodine concentration was determined in 1458 of them. The mean ± SD of urinary iodine concentration was 13.0 ± 7.4 μg/dl, but 38% of urinary iodine concentration were below 10 μg/dl and 10% were under 5 μg/dl. The prevalence of goitre was 4.1% in boys and 3.1% in girls. There was a negative correlation between urinary iodine concentration and thyroid volume (p < 0.001). Therefore, the results of the 'Thyromobile' project show that the places, investigated in France, are not in an area of endemic goitre due to iodine deficiency. However, other epidemiological studies must be done to provide further information about iodine supply in all parts of France.