At the root of the success of modeling, design, reengineering, and running business processes is effective use and support of organizational knowledge. Therefore, the relationships between a business process and organizational knowledge should be clearly documented. Several methods have already been elaborated that introduce the process dimension into knowledge management or a knowledge concept into business process modeling. However, the usability of these methods is restricted either by applicability only to knowledge-intensive processes or by relying on sophisticated or uncommon modeling techniques. Building on the experience accumulated by researchers working at the intersection of business process modeling and knowledge management, this paper proposes to extend the well-known Business Process Modeling Notation with the knowledge dimension so that using a common modeling technique it would be possible to relate different forms of knowledge, information and data to the business process model. The approach is demonstrated by a case study from a data base integration project at the Bioinformatics Company.