As a reliable method, Laser induced breakdown spectroscopy (LIBS) is widely applied to elemental analysis in different fields. In this research, LIBS was used to analyze pharmaceutical tablets. For this purpose, spectra from eight samples of three pharmaceutical classes were acquired; and after peaks recognition, they were investigated by principal component analysis (PCA) and artificial neural network (ANN). According to the results, due to the similarity of the main elements of different samples, it is difficult to distinguish them by spectra; therefore, PCA was used to make a better comparison between the samples. Apart from that, unknown samples were identified and predicted through the ANN.