This paper presents a Business Rule Extraction tool for COBOL systems. Starting from a COBOL program, we derive a model-based representation of the source code and we provide a set of model transformations to identify and visualize the embedded business rules. In particular, the tool facilitates the definition of an application vocabulary and the identification of relevant business variables. In addition, such variables are used as starting point to slice the code in order to identify business rules, that are finally represented by means of textual and graphical artifacts. The tool has been developed as an Eclipse plug-in in collaboration with IBM France.