The aging of concrete structures and corrosion of reinforcing steel has resulted in an increasing need of repairs and strengthening. New repair materials and methods are developing which is not followed with enough experience on their performance. The selection of the best repair option should be based on technical and economical (apart from social) considerations and, therefore, its seems that a life cycle cost analysis, (LCCA) is the most suitable methodology for making an intercomparison between them. However, due to a lack of experience and of rigorous data, LCCA is very often not feasible. In this paper an alternative is presented: the repair index method, RIM. It is based on defining a set of requirements: safety, serviceability, environmental impact, durability and economy, that are quantified through repair performance indicators, RPI, ranked in four levels of importance (from 1 through 4). The RPI are averaged for each requirement, R, then, a repair index, RI, is calculated for comparative purposes through an algorithm for each repair option in each structure. The algorithm may suffer some objectivity, but when applied with some assumptions, can be an alternative to LCCA.