The aim of this study is to improve the mechanical resistance of a structural bonded repair on a plate made of Carbon Fiber Reinforced Plastic (CFRP) with a circular damage. A first approach is made by doing a complete analysis of the type of repair which consists in a lay-up of wet carbon prepreg plies. Experimental and numerical results are produced, which give reference results for this basic model of repair under tension load. Then, the evolution of these results is examined according to the variation of critical parameters, such as bonding length and overlapping length, which leads to optimal values to improve the repairing efficiency. Finally, the results provide the opportunity to reduce the amount of repairing plies for an even better repair performance.