One of the issues identified in natural resources management leading to overexploitation has to do with a limited or weak legislative framework. The aim was to analyze a quantitative approach evaluating the contribution of different legislative instruments of Mexico on coastal ecosystems sustainability. A case study was employed, and a practical appraisal method that allows identification of sustainability criteria embedded in the legislative instruments was generated. Forty-three Mexican legislative instruments were evaluated, and 60 sustainability attributes were considered. Trends and consistency regarding objectives, times of law application, orientation to systems or to resources, legal and institutional interactions, scientific support, unpredicted impacts of productive activities (non-regulated) and performance evaluation were analyzed. A multivariate analysis was performed to map the interrelations among legislative instruments. On a global scale, legislative instruments only fit in 25% of global sustainability attributes when compared with the two references defined as ideal. Multiple objectives and some systemic approaches were well represented among the analyzed instruments, and regulation of some coastal areas and ecosystems, such as reefs, need to be deeply strengthened. It can be concluded that the proposed approach is useful to obtain a rapid appraisal to evaluate the overall contribution of legislative instruments on ecosystems sustainability. This information will guide legislative authorities in the development of instruments that could strengthen legislative framework in order to efficiently promote ecosystems sustainability.