Wavelength dispersive X-ray fluorescence (WDXRF) is emerging as a powerful and efficient tool for detecting chemical changes in crops affected by plant-parasitic nematodes. These microscopic pests target plant roots, causing nutrient imbalances, stunted growth, and ultimately plant death. Given the increasing threat these nematodes pose to global food security, early detection is essential. However, traditional diagnostic methods, such as DNA analysis and physical extraction techniques, can be time-consuming and complex. As the need for more rapid solutions grows, advanced spectroscopic methods, including WDXRF, LIBS, FTIR, UV-Vis, and ICP-OES, are becoming invaluable tools for monitoring plant health. These techniques allow for the identification of subtle chemical alterations in plants caused by nematode infestations, enabling earlier intervention and reducing the reliance on harmful chemical treatments. By offering faster, more accurate analysis, spectroscopic methods like WDXRF improve our understanding of plant health, support more efficient pest management strategies, and contribute to sustainable agricultural practices. This chapter explores the application of WDXRF in diagnosing nematode-induced damage in crops, demonstrating its potential to enhance food security while promoting environmentally friendly farming approaches.