Nanoscale zero-valent iron (Fe 0 ) was synthesized for nitrate denitrification. The reduction efficiency of nitrate decreased quickly with increasing initial pH value, increased considerably with the increasing dosage of nanoscale Fe 0 , and did not vary much with initial nitrate concentrations changing from 20 to 50mgl −1 when the excessive amount of nanoscale Fe 0 was utilized. With reductive denitrification of nitrate by nanoscale Fe 0 , the removal rate of nitrate reached 96.4% in 30min with nanoscale Fe 0 dosage of 1.0gl −1 and pH in 6.7, and more than 85% of the nitrate was transformed into ammonia. Kinetics analysis in batch studies demonstrates that the denitrification of nitrate by nanoscale Fe 0 involves reaction on the metal surface, which fits well the pseudo-first order reaction with respect to nitrate concentration. The observed reaction rate constant of reductive denitrification of nitrate was determined to be 0.086min −1 with a nanoscale Fe 0 dosage of 1.0gl −1 and pH in 6.7. Fast and highly effective denitrification can be achieved by nanoscale Fe 0 compared with commercial Fe 0 powder, this is due to the extremely high surface area and high reactivity for nanoscale Fe 0 , which can enhance the denitrification efficiencies remarkably.