This chapter provides an overview of electromagnetic interference (EMI) and the potential of magnetic nanocomposites for EMI shielding. EMI, a significant issue in the modern technological landscape, disrupts the operation of electronic devices and systems across various industries. The chapter highlights the importance of understanding EMI's underlying principles and its wide-ranging impacts, from minor disturbances to severe system failures. It also discusses the global research trends in magnetic nanocomposites, based on data from the Scopus database, showing a peak in research activity in 2021 followed by a notable decline in subsequent years. The chapter emphasizes the need for further investigation into the reasons behind these trends, such as the exhaustion of main research topics or a shift towards other emerging fields. Additionally, it outlines the impact of EMI across different sectors, underscoring the urgent requirement for effective EMI shielding materials.This chapter provides an overview of electromagnetic interference (EMI) and the potential of magnetic nanocomposites for EMI shielding. EMI, a significant issue in the modern technological landscape, disrupts the operation of electronic devices and systems across various industries. The chapter highlights the importance of understanding EMI's underlying principles and its wide-ranging impacts, from minor disturbances to severe system failures. It also discusses the global research trends in magnetic nanocomposites, based on data from the Scopus database, showing a peak in research activity in 2021 followed by a notable decline in subsequent years. The chapter emphasizes the need for further investigation into the reasons behind these trends, such as the exhaustion of main research topics or a shift towards other emerging fields. Additionally, it outlines the impact of EMI across different sectors, underscoring the urgent requirement for effective EMI shielding materials.