Intensive vegetable cultivation often leads to substantial accumulation of nitrate (NO3 − -N) in the topsoil, thus posing serious threat to groundwater safety by NO3 − -N leaching and food safety by excessive uptake of NO3 − -N by vegetables. Reductive soil disinfestation (RSD) may remove over-accumulated NO3 − -N in the topsoil due to its water-saturated, strongly reductive, and carbon-rich characteristics that favor the removal of NO3 − -N via denitrifcation, immobilization, and leaching. However, how RSD affects the fates of NO3 − -N of the topsoil in intensive vegetable lands remains largely unknown. Here, a soil column experiment using 15N tracing technique was conducted to quantify the fates of NO3 − -N in the topsoil under RSD in six representative intensive vegetable soils in China. The results showed that an average of 99.7% of the added 15NO3 − -N in the topsoil was removed by RSD in all intensive vegetable lands. Denitrifcation in the entire soil profle and leaching of NO3 − -N into the subsoil were responsible for 21.8–78.3% and 14.9–68.4% of the removed 15NO3 − -N, respectively, whereas microbial NO3 − -N immobilization and dissimilatory nitrate reduction to ammonium in the topsoil played a negligible role in removing 15NO3 − -N. A tradeoff was found between denitrifcation and leaching of NO3 − -N into the subsoil among the six soils under RSD. The structural equation modeling demonstrated that the positive effects of RSD on topsoil pH, dissolved organic carbon, and bacterial abundance decreased the leaching of NO3 − -N into the subsoil by enhancing denitrifcation. Overall, the results provided the frst direct evidence for complete removal of NO3 − -N in the topsoil by RSD. Such an evidence has implications for controlling NO3 − -N accumulation through implementing RSD in intensive vegetable soils