Introduction. Public procurement is an essential instrument for the execution of the procurement of goods, services, works and consultancies, and for the satisfaction of the needs of society in Ecuador. From this perspective, the preparatory phase, especially the definition of institutional need, plays a determining role in the efficiency and effectiveness of contractual processes. Objectives. The objective of this paper is to analyze the impact of a correct and adequate definition of need on the public procurement processes of the Rural Parish Decentralized Autonomous Government (GADPR) of Shell, Pastaza province, in the period 2022–2023. Methodology. The research adopted a qualitative approach, descriptive-analytical-propositional, based on the documentary review of contracting files, current regulations and reports of the control entity, the design used was non-experimental of a cross-sectional type, with qualitative predominance and descriptive quantitative support through a survey applied to the same servers, integrated through a triangulation matrix. Results. The results showed that the processes showed declared need, but technical justification, previous studies, specifications and referential budget that did not meet the criteria provided for in the Organic Law of the National Public Procurement System and its Regulations, generating deserted processes, delays, contractual reforms, inefficient use of public resources and observations of the control entity. Conclusions. It is concluded that it is a priority to strengthen the preparatory phase through a set of technical guidelines (formats, checklist, risk matrix and training), which is essential to optimize public procurement processes and meet institutional objectives. General area of study: Public Administration. Specific area of study: Public Procurement. Type of article: original.