Fuzzy querying systems allow queries to be more or less satisfied. Then, the results of a query are ranked according to their degree of satisfaction. The need for fuzzy querying systems has increased since the arrival of multimedia data in the field of database management systems. In fact, queries on multimedia data are often an imprecise description of their content; therefore, queries should not be interpreted strictly. To model fuzzy querying in a multimedia database, we propose the definition of a fuzzy querying system based on fuzzy logic and applied in an object-oriented environment. In this way, we define new data types, such as fuzzy collections and fuzzy predicates, and we also define extensions of classic object-oriented retrieval operators, such as the operators of AQUA (A QUery Algebra) and OQL (Object Query Language). The objective of our work is to define a general framework on which applications can fully exploit the graduality associated with their processing tools.