This paper aims to publicize the results of the dissertation "The Filière of Medicinal Plants in Brazil - A Brief Outline from Dynamic Economic Approaches" concerning the perception of it's actors with the institutional sphere. The approaches utilized were from the Theory of Transaction Costs, the Evolutionist Theory and the Theory of Corporate Coherence. The techniques employed were the interview and the nonparticipant observation. It follows that the two factors which affected the most the transaction costs and which end up defining the choice of the contractual arrangements by the concerns in the sample of the filière studied, are the uncertainty and the specificity of assets. It's concluded that an asymmetry of information and specific assets among the actors of the filière exists, which enables the support of the appropriation of the gains by actors with the greatest bargaining power, due to a dysfunction regulating and inducing the development in the institutional sphere.