In this paper, we present our Form-driven approach for reverse engineering of relationa databases. This methodology uses the information extracted from both form structure and instances as a database reverse engineering input using an interaction with a user. Through a combination of forms structures and data instances analysis, forms relational sub-schemas and their constraints are derived. These relational sub-schemas are mapped to object sub-schemas, which will be merging into global object-oriented schema that presents the whole underlying databases. The resulting global object-oriented schema must be validated as a rich and correct representation of the application domain. Key words: relational databases, reverse engineering, object-oriented databases, forms, integration, validation.