Aims: White spot syndrome virus (WSSV) continues to be the most pathogenic virus among the crustacean aquaculture causing mass mortality. In the present study, we established a one-step, single tube, real-time accelerated loop-mediated isothermal amplification (real-time LAMP) for quantitative detection of WSSV. Materials and Methods: A set of six specially designed primers that recognize eight distinct sequences of the target. The whole process can be completed in 1 h under isothermal conditions at 63°C. Detection and quantification can be achieved by real-time monitoring in an inexpensive turbidimeter based on threshold time required for turbidity in the LAMP reaction. A standard curve was constructed by plotting viral titre against the threshold time (Tt) using plasmid standards with high correlation coefficient (R2 = 0·988). Conclusions: Sensitivity analysis using 10-fold dilutions (equivalent to 35 ng l-1 to 35 ag l -1) of plasmid standards revealed this method is capable of detecting upto 100 copies of template DNA. Cross-reactivity analysis with DNA/cDNA of IHHNV, TSV, YHV-infected and healthy shrimp showed this method is highly specific for quantitative detection of WSSV. Significance and Impact of the Study: WSSV real-time LAMP assay appears to be precise, accurate and a valuable tool for the detection and quantification of WSSV in large field samples and epidemiological studies. © 2008 The Society for Applied Microbiology.