Objective: Mild iodine deficiency was first documented in Campania in the 1990s. We assessed the urinary iodine nutritional status of schoolchildren in Campania before the introduction of legislation for salt iodization and compared the findings with previous results to evaluate to what extent "silent" iodine prophylaxis, which accompanies socioeconomic advances, affects iodine status. Methods: We examined 10552 schoolchildren aged 9-13 y from the five Campania provinces. The study was conducted from April 1999 to October 2002. Urinary iodine excretion was measured in morning urine samples with the AutoAnalyzer 3, an automated system based on the Sandell-Kolthoff reaction. Data were interpreted according to World Health Organization criteria. Results: The median urinary iodine excretion level in Campania was less than 100 mu mu g/L, which indicates insufficient iodine intake. Mild iodine deficiency was identified in all provinces, namely Napoli, Salerno, Caserta, Avellino, and Benevento, with median urinary iodine excretions of 87, 81, 72, 64, and 61 mu g/L, respectively. Overall, the analysis of frequency distribution showed values below 50 and 100 mu g/L in 32% and 61% of children, respectively. These values were lower than those previously reported for Campania. Conclusion: This study confirms that Campania is a mild iodine deficiency area. The decrease in iodine deficiency versus previous studies indicates that silent prophylaxis plays a relevant role in this condition, but it is not sufficient to eradicate it. Our data will serve as a basis for future evaluations of iodine status in Campania. (C) 2009 Elsevier Inc. All fights reserved.