The Rare-Earth Elements (REE) distribution pattern, along with the 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb isotopic ratios, can assist nuclear forensics practitioners and safeguards in tracing a uranium nuclear material back to its origin or in verifying the declared origin or accountancy. The present paper shows the first "in-house" analytical method, developed within the "Horia Hulubei" National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), with the purpose of monitoring REE and lead impurities in uranium oxide samples. A total of nine spiked replicate samples and three subsamples of UO 2 Merck testing material were subject to the developed procedure. The method was validated in terms of selectivity, trueness (recovery), determination of the quantification limit, precision (repeatability) and ruggedness, proving that is suitable for monitoring REE and lead impurities in the tested matrix.