Accurate stopping powers for 7-Li ions in four (co) polymers were measured using the transmission technique in the energy range of 0.5 - 10.5 Mev. The estimated uncertainty in the stopping power values is ~2.5%. A comparison of the experimental data is made with various parametrizations of the stopping power found in the literature. deviations of the parametrizations from our experimental data range from 5 to 20%. ; JRC.D-Institute for Reference Materials and Measurements (Geel)