A process for preparing trinitrotoluene (TNT) in which toluene is treated with nitric acid having a concentration of about 90% to about 99%, and preferably about 98% to about 99%, by weight at a temperature of less than about 60° C., and preferably less than 30° C., to produce high purity dinitrotoluene. The resulting dinitrotoluene is then treated with nitric acid having a concentration of about 98% to about 99% by weight and trifluoromethane sulfuric acid to produce high purity TNT.