Electronic stopping powers for 0.05-10 Me V protons in a group of organic materials are systematically calculated. The calculations are based on Ashleys dielectric model, and an evaluation approach of optical energy loss function is incorporated into Ashleys model because no experimental optical data are available for most of the organic materials under consideration. The Barkas-effect correction and Bloch correction are included. The proton stopping powers for the considered organic materials except for mylar in the energy range from 0.05 to 10 MeV are presented for the first time. The results may be useful for studies of various radiation effects in these materials and for space research.