The serum concentrations of perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) were determined in 230 subjects of the Italian general population. Participants were enrolled in 2008 in two Italian towns (Brescia, Northern Italy, and Rome, Central Italy) and belonged to the three age ranges: 20-35. years, 36-50. years, and 51-65. years.PFOS and PFOA were quantified by HPLC interfaced to a mass spectrometer operating in the electrospray negative mode. Data were acquired using multiple reaction monitoring (MRM). The isotope dilution technique was applied throughout.The median serum concentrations of all participants were 6.31ngg-1 and 3.59ngg-1 for PFOS and PFOA, respectively, and the pertinent 90th percentiles were 12.38 and 6.92.Men had higher concentrations of PFOS and PFOA than women, regardless of age. The differences were statistically significant in the 20-35 and 36-50. years groups, but not in the 51-65 group.An increase of PFOS and PFOA serum concentrations with age was observed. The Median test showed a statistically significant difference (p≪0.01) between the three age groups for both PFOS and PFOA when applied to the entire dataset (males and females). When the test was applied to the groups of males and females separately, a significant difference was observed for females (p≪0.005) but not for males (p>0.1).The observed strong correlation between PFOS and PFOA concentrations suggests same or similar exposure routes. © 2010 Elsevier Ltd.