Carbon nanofibers (CNFs) are plasma etched by using cold plasma of helium and air for different time durations. Changes in surface characteristics of CNFs due to plasma treatment was studied with Raman spectroscopy, BET surface area analyzer, and atomic force microscopy (AFM). Raman spectroscopic studies showed that, plasma treatment is imparting enhanced degree of disorder for CNFs. While AFM studies indicated enhancement in the surface roughness due to plasma treatment. Laminated (2D) carbon fiber reinforced epoxy matrix (C-epoxy) composites were fabricated with the addition of 0.5-wt% of plasma-etched CNFs and evaluated the mechanical properties of the prepared composites. Results indicate that, plasma-etched CNFs can improve the mechanical properties of CFRPs significantly as compared to untreated CNFs. Carbon nanofibers (CNFs) are plasma etched by using cold plasma of helium and air for different time durations. Changes in surface characteristics of CNFs due to plasma treatment is studied with Raman spectroscopy. Raman spectroscopic studies show that plasma treatment is imparting enhanced degree of disorder for CNFs. Plasma-etched CNFs-C-epoxy composites can improve the mechanical properties of CFRPs significantly as compared to untreated CNFs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.