Objectives: The evaluation of toxicological levels of potential genotoxic impurities in bulk drug and its commercial forms was treated as significant as well as very difficult issue. The European Medicines Agency guided that 1.5 μg/day intake of a genotoxic impurity was treated as given as acceptable for most of the pharmaceutical products. In view of this, this study intended to establish a simple and sensitive LCMS method for the quantification of potential genotoxic impurities (PGIs) such as impurity 1, 2 and 3 in larotrectinib pure drug and its drug product.