pg4DB: A fuzzy object-relational system. Object-relational systems combine the robustness of the relational data model with the powerful modeling capabilities of the object-oriented paradigm. Object-Relational Database Management Systems (ORDBMS) allow us to implement a set of relations to store and retrieve objects coming from a hierarchy of classes. If we want to manipulate imprecise objects in this kind of systems, we have to properly extend them. In this paper we introduce pOSTgRESQL Fuzzy Object Relational DataBase (pg4DB), a framework that supports the management of fuzzy objects in ORDBMS such as PostgreSQL. As we will see pg4DB allows users to create imprecise objects and operate with them using object-relational SQL compliant sentences.