The theory of contracts assumes that human nature is essentially opportunistic, and economic agents protect themselves against adverse selection and moral hazard by elaborating contracts. In the case of irrigated areas in the Brazilian northeast, such contracts are not necessarily formal. That is, arrangements based on economic agent’s word are common. The data used are from acerola producers in the Petrolina-Juazeiro irrigation project. The empirical model was tobit, given that the dependent variable was characterized by a truncated distribution. The results showed that the decision to engage on contractual relations is fundamentally defined by the degree of dependence of the farmer in respect to the processing industry. Furthermore, past experience of contractual relationship with the processing industry is a strong determinant of the individual’s behavior.