The reduction of 2, 4, 6-trinitrotoluene (TNT) in aqueous solution using nanoscale zero-valent iron (nZVI) was investigated. The results showed that the pseudo-first order reaction law fit the reduction of TNT. The measured apparent rate constant (Kobs) of TNT on nZVI (0.761 h−1) was 7.8-fold than on conventional iron powders (0.0979 h−1) at 303 K. The apparent activation energy (Ea) of nZVI reducing TNT was found to be 24.85 KJ/mol, which was decreased by 60% compared to employing conventional iron powders. The apparent rate constant ofTNTreduction on nZVI also can beimproved by an increase in nZVI concentration, reaction temperature and a decrease of pH.