The present work has, as its object, the washout clause in buy and sell contracts for the delivery of soybean future harvest, quoted in dollar, inquiring about its lawfulness regarding Civil Code's art. 421-A, and the possibility of a judicial review. This study is justified by de institute's absence of dogmatic and normative delimitation, which requires an understanding of its function and legal nature, to conform it with positive law. The specific objectives run through the description of the dynamics of long-term contracts involving commodities and the consequences of factual changes external to the contract, although related to it when there is a dollar and a rural producer's respective delivery variation. Being so, it debates the legal nature of the clause, basing it on the indemnity and the penal clause institutes. The results point to the legality of the washout clause and its translation as its penalty clause. This research's methodology is bibliographic and deductive, and uses a descriptive analysis.
