This article analyses the need of developing an institutionalized model of ex post evaluation in the Federal Entities in Mexico. The absence of evaluation mechanisms in the States reduces the potential efficacy of local legislation frequently approved and amended without empirical knowledge of its effects. In 2015 a bill proposing the creation of a monitoring and evaluation system was presented in Sonora. This article analyses the strengths and weaknesses of the project’s model (based upon a protagonist position of the Parliamentary Committees) compared to the Swiss model which employs a constitutional based federal evaluation system coexisting with local cantonal models.