The UV-absorption spectra of cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) and cyclo-1,3,5,7-tetramethylene-2,4,6,8-tetranitramine (HMX) are strongly overlapping and do not allow their direct determination without previous separation by conventional methods. A partial. least squares method (PLS) in a multicomponent analysis provides a sensitive and accurate technique for the analysis of complex mixtures with strong overlapping spectra. The experimental calibration matrix was designed with 15 samples. The concentration varied between 0.584 mug/ml and 10.220 mug/ml for HMX, and between 0.400 mug/ml and 8.000 mug/ml for RDX. The cross-validation method was used to select the number of factors. To check the accuracy of the proposed method, the optimized model obtained by using PLS-2 was applied to the determination of these compounds in industrial samples.