Agricultural cooperatives have diversified their businesses in response to economic, financial and political changes. Despite its economic and social importance and its distinct organizational characteristics, few studies address diversification in cooperatives. When diversifying, new activities require the cooperative and members to adapt to the demands of end markets, emphasizing vertical coordination and focusing on business terms. In addition, the cooperative begins to coordinate several production chains with the member. As a result, some doubts arise regarding the efficiency of the cooperatives' governance structure for these activities and the impact on other associated activities. With this, the objective was to present a study proposal aiming to identify how the diversification strategies adopted in agricultural cooperatives relate to the governance structure and what the consequences are for other existing exchange relationships. To this end, a theoretical discussion was held according to the complementarity of Transaction Cost Economics (ECT) and Measurement Cost Economics (ECM), with the support of a bibliographical survey on the diversification strategy in cooperatives and the relationship with members.