The purpose of this research is to determine the effect of atmospheric pressure plasma treatment on Mode I strain energy release rate (GIC) and failure mode of bonded peel ply prepared carbon fiber reinforced polymer composites. Previous research showed that Toray T800/3900 carbon fiber reinforced epoxy composites prepared with Precision Fabrics Group 52006 nylon peel ply and bonded with MetlBond 1515-3M structural film adhesive failed in adhesion at low fracture energies when tested in the double cantilever beam (DCB) configuration. Other research suggested that plasma treatment could be able to activate these “un-bondable” surfaces and result in good adhesive bonds. Nylon peel ply prepared 177°C cure carbon fiber reinforced epoxy laminates were treated with atmospheric pressure plasma after peel ply removal prior to bonding. Surface characterization methods, including contact angle (CA), Fourier transform infrared (FTIR) spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to determine how plasma treatment changed nylon peel ply prepared surfaces. CA can be used to measure surface energy of a composite prepared for adhesive bonding. This information can help understand one requirement of adhesion: surface wetting of the adherend by the adhesive. FTIR and XPS can be used to measure composite surface chemistry, which can help understand another requirement of adhesion: the formation of chemical bonds between the adherend and adhesive. FTIR and XPS can also be used for the identification of contaminants, which can inhibit adhesive bonding. DCB specimens were bonded with MetlBond 1515-3M and tested to determine failure mode and GIC. Plasma treated samples had acceptable failure modes and fracture energies that were triple that of peel ply only samples. It was demonstrated that atmospheric pressure plasma was able transform poor bonding surfaces to good bonding surfaces.