In this paper we elected to nitrate p-xylene because this compound has only one mononitro- and trinitro- isomer. Trinitro-p-xylene was used as a starting material for the synthesis of other compounds in subsequent work. The mononitration of p-xylene can be easily carried out at 30 degrees C. Nitro-p-xylene is easily nitrated to dinitro-p-xylene at a temperature of 80 degrees C. The trinitro-p-xylene can be obtained at 120 degrees C. Single crystals of 2,3-dinitro-p-xylene and 2,3,5-trinitro-p-xylene were grown using the slow cooling method and we report the X-ray structure of the former. The thermal decomposition of the compounds was studied using differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) techniques and FT-IR. The target compounds were also characterized by (1)H-NMR, (13)C-NMR and MS.