High performance thin layer chromatography (HPTLC) has been used for the simultaneous determination of pentaerythritol tetranitrate (PETN) and 2,4,6-trinitrotoluene (TNT). With this aim, the spots were developed on silica gel 60 F(254) layers with petroleum ether-acetone (2:1 v/v). Both PETN and TNT compounds were separated from other constituent materials, and were developed at the same speed, by this solvent system. Then ultraviolet (UV) spectra of these materials were recorded with TLC-scanner3 of CAMAG Company, and partial least squares regression-2 (PLSR-2) method was applied for the calibration and quantitative determination of these materials. The figure of merit (FOM) of this method was determined, and the method was applied for the analysis of an artificial sample.