This study presents high-precision isotopic analyses of USGS reference materials using both TIMS and MC-ICP-MS. The Pacific Centre for Isotopic and Geochemical Research (PCIGR) analyzed a wide range of USGS reference materials, including basalt, andesite, rhyolite, syenite, granodiorite, and granite. These materials are well-characterized geochemically, but there is no systematic methodology or database for their radiogenic isotopic compositions. The study provides a comprehensive database for the isotopic community and compares the precision and accuracy of isotopic analyses using both TIMS and MC-ICP-MS methods. The results show that the first- and second-generation USGS reference materials have homogeneous Sr and Nd isotopic compositions. Nd isotopic compositions by MC-ICP-MS and TIMS agree within 15 ppm for all reference materials. Interlaboratory MC-ICP-MS comparisons show excellent agreement for Pb isotopic compositions, although reproducibility is not as good as for Sr and Nd. A careful leaching experiment on three first- and second-generation reference materials indicates that Pb isotopic heterogeneity may be due to contamination by steel (mortar/pestle) used to process the materials. Contamination also accounts for high concentrations of certain trace elements in USGS reference materials. The study highlights the importance of an integrated analytical approach to better understand potential issues during sample processing and analysis. The results demonstrate that the first- and second-generation USGS reference materials have similar Sr and Nd isotopic compositions, and that Nd isotopic compositions can be measured with comparable accuracy and precision using either TIMS or MC-ICP-MS. However, Pb isotopic ratios require leaching to remove potential contamination from the original sample preparation. This compromises the use of these materials as glass reference materials for laser-ablation studies involving Pb concentrations or compositions. The study also shows that leaching reduces Pb isotopic differences between first- and second-generation reference materials, indicating that contamination is the cause rather than sample heterogeneity or leaching issues. The results provide a valuable database for the isotopic community and highlight the importance of careful sample preparation and analysis.This study presents high-precision isotopic analyses of USGS reference materials using both TIMS and MC-ICP-MS. The Pacific Centre for Isotopic and Geochemical Research (PCIGR) analyzed a wide range of USGS reference materials, including basalt, andesite, rhyolite, syenite, granodiorite, and granite. These materials are well-characterized geochemically, but there is no systematic methodology or database for their radiogenic isotopic compositions. The study provides a comprehensive database for the isotopic community and compares the precision and accuracy of isotopic analyses using both TIMS and MC-ICP-MS methods. The results show that the first- and second-generation USGS reference materials have homogeneous Sr and Nd isotopic compositions. Nd isotopic compositions by MC-ICP-MS and TIMS agree within 15 ppm for all reference materials. Interlaboratory MC-ICP-MS comparisons show excellent agreement for Pb isotopic compositions, although reproducibility is not as good as for Sr and Nd. A careful leaching experiment on three first- and second-generation reference materials indicates that Pb isotopic heterogeneity may be due to contamination by steel (mortar/pestle) used to process the materials. Contamination also accounts for high concentrations of certain trace elements in USGS reference materials. The study highlights the importance of an integrated analytical approach to better understand potential issues during sample processing and analysis. The results demonstrate that the first- and second-generation USGS reference materials have similar Sr and Nd isotopic compositions, and that Nd isotopic compositions can be measured with comparable accuracy and precision using either TIMS or MC-ICP-MS. However, Pb isotopic ratios require leaching to remove potential contamination from the original sample preparation. This compromises the use of these materials as glass reference materials for laser-ablation studies involving Pb concentrations or compositions. The study also shows that leaching reduces Pb isotopic differences between first- and second-generation reference materials, indicating that contamination is the cause rather than sample heterogeneity or leaching issues. The results provide a valuable database for the isotopic community and highlight the importance of careful sample preparation and analysis.