The paper describes surface treatment methods to improve adhesion between copper and vinyl ester in glass fiber-vinyl ester composites. Surface treatment methods were developed for commercially available copper that was optimized for epoxies and adhesion performance was compared based on 90 degrees peel strength measurements. Four surface treatments for copper were tested: (i) co-cured Epon/vinyl ester; (ii) fully cured Epon; (iii) epoxy film adhesive; and (iv) gamma-MPS silane along with two baseline systems: copper/vinyl ester and copper/epoxy. Measured average peel strengths for the surface treatments were 21%, 101%, 110% and 91% of the baseline copper/vinyl ester system, respectively. Compared to the copper/epoxy system, fully cured Epon, epoxy film adhesive and the silane treatment generated comparable adhesion between copper and vinyl ester. For all samples tested, mixed cohesive/adhesive failure modes were observed. Overall, the surface treatment with the silane coupling agent is the most appropriate method for obtaining comparable and uniform performance compared to copper/glass fiber/epoxy system (FR4 materials).