Due to the importance of bottled mineral water in human diet with special regard to children in lactation period, a monitoring of natural radioactivity in some bottled mineral waters produced in Italy was performed. Gross alpha and beta activities and Ra-226 U-238, U-234, and Po-210 concentrations were measured. Gross alpha and beta activities were determined by standards ISO 9696 and ISO 9697; for 226 Ra determination liquid scintillation was used. The U-238 and U-234 concentrations were determined by alpha spectrometry after their separation from matrix by extraction chromatography and electroplating. Po-210 was measured by alpha spectrometry. The results revealed that the concentrations (mBq L-1) of Ra-226, U-238, U-234, and Po-210 ranged from <10.00 to 52.50, from <0.17 to 89.00, from <0.17 to 79.00, and from <0.04 to 21.01, respectively. Uranium and radium concentrations do not reach the relevant recommended derived activity concentration (DWC). For polonium concentration, none of the samples reaches the relevant DWC in the case of adults and children, but one sample exceeds this value for infants. The dose contribution for different classes of age was calculated using the dose coefficient factors reported by EC Directive 96/29 EURATOM and certain annual intake. For children and adult age class, the calculated doses are quite similar and lower than 0. 1 mSv y(-1) for infants (<1 y) in three cases the calculated dose ranges from 0. 11 to 0. 17 mSv y(-1) (C) 2007 Elsevier Ltd. All rights reserved.