Business process models, often modelled using graphical languages like UML, serve as a base for communication between the stakeholders in the software development process. To fulfill this purpose, they should be easy to understand and easy to maintain. For this reason, it is useful to have measures that can give us some information about understandability, analyzability and maintainability of a business process model. Shao and Wang have proposed a cognitive complexity measure[19]. It can be used to estimate the comprehension effort for understanding software. This paper discusses how these research results can be extended in order to analyze the cognitive complexity of graphical business process models.