Abstract— The use of computer simulations has significantly increased in modern metal casting over the past few years. With these simulations, the prediction and minimization of casting defects has become very convenient without following the conventional trial-and-error method of metal casting. This study presents the utilization of simulation tools in predicting two important casting defects, hotspots and porosity. An aluminum impeller with a moderately complex geometry is selected for which the initial and modified casting layouts are simulated using MAGMASoft. Hotspots and porosity are predicted and minimized using simulations and the impeller is cast based on the modified casting layout with minimal defects. Simulations and experimental results are found to be in good agreement. It is concluded that a casting process can be accurately modeled using simulations together with defect prediction and minimization. Moreover, the predicted high quality of castings can be achieved if the process is done in a controlled manner while exactly matching the parameters used in simulations.