The stopping power of Formvar and Mylar polymeric materials for energy region (0.1 to 1.0) MeV/nucleon 19F, 23Na, 24Mg, 27Al, 28Si, 31P, 32S, 35Cl, and 40Ar ions have been determined. The energy loss and stopping power of Mylar were calculated for 11B having energies between 0.31 and 0.85 MeV/nucleon. In fact, the factor ξe and exponential function f(E) involved in Lindhard, Scharff, and Schiott (LSS) theory has been modified in light of the available simulation electronic stopping power values. The results obtained by the LSS modified theory and Monte Carlo simulations are compared with MSTAR, the SRIM predictions code, and experimental data. The obtained results show a close agreement qualitatively with MSTAR, experimental data, and those generated by the SRIM computer code.