The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantify as they can be used to evaluate whether the casting process will be successful. In addition, the properties can potentially be implemented in a computational fluid dynamics model which can be used as a tool to optimize the process. The rheological experiments are carried out on a MCR 502 rheometer with a new module for characterizing granular materials. The new module enables viscosity measurements of the green sand as function of the shear rate at different flow rates, i.e. 0, 2, 4, 6, 8, 10, 12 and 15 L/min. The results show generally that the viscosity decreases with both the shear- and flow rate. In addition, the measurements show that the green sand flow follows a shear-thinning behaviour even after the full fluidization point.