Tomato leaf curl New Delhi virus (ToLCNDV) is a serious threat to global crop productivity. Timely and accurate detection is essential for managing the disease effectively. While initial diagnostic efforts depended on visible symptoms, recent advances have led to more precise and reliable methods. Serological techniques such as ELISA—including DAC-ELISA, DAS-ELISA, and IC-ELISA—have proven effective in detecting viral antigens, especially when paired with molecular diagnostics. Among nucleic acid-based tools, conventional, nested, and multiplex PCR facilitate qualitative detection, while quantitative PCR (qPCR) enables early diagnosis through accurate viral load quantification. In the field, isothermal amplification methods like LAMP and RPA deliver rapid results without the need for advanced laboratory infrastructure. Newly emerging techniques such as CRISPR-LAMP and nanotechnology-based biosensors, using gold nanoparticles for scanometric DNA detection, are pushing the boundaries of sensitivity and specificity. Together, these diagnostic innovations-from traditional assays to cutting-edge technologies-offer powerful means to monitor and control ToLCNDV, safeguarding agricultural productivity.