The production of desserts and fruit jellies is a traditional agribusiness activity in the south of Brazil, especially in Pelotas, Rio Grande do Sul. However, the Brazilian commercial opening that was processed in the beginning of the 1990’ years, it influenced negatively this segment, mainly in relation to the peach. This resulted in a new roll of conditions that culminated in the need of a revaluation of the transactional behavior among the agents involved in this segment. In this aspect, it is necessary to consider that the agribusiness system capacity of organization depends on the contractual arrangements that are established among them. In spite of these contractual relationships that causes an influence on the system efficiency it depends, not only of the assets involved characteristics and the agents’ behavior, but the institutional, organizational and technological aspects also influence it. About it, this paper intent to identify the presence of transaction costs in the contractual relationships established in the peach agribusiness system in Pelotas. In this sense, the analysis locates inside of the New Institutional Economy approach and in the Transaction Costs Economic theory.