Inductively coupled plasma mass spectrometry (ICP-MS) has been recognized by ICH Q3D(R2), USP <232>/<233> and the 2025 edition of the Chinese Pharmacopoeia as the preferred technique for elemental-impurity determination in pharmaceuticals, owing to its sub-ppt limits of detection, nine-order dynamic linear range, and simultaneous multi-element detection capability. After a systematic introduction to the fundamentals and characteristics of ICP-MS, this review summarizes the most recent applications in quantifying heavy-metal residues, trace elements, and elementary speciation; discusses critical technical challenges—including matrix interference, species transformation, and sample preparation, and outlines future perspectives such as high-resolution mass spectrum, multidimensional hyphenation, and intelligent quality evaluation, so as to provide a reference for the control of elemental impurities in the full life circle of medicinal products.