To gain insight into the hydrodynamics of spout-fluid beds, an experimental and numerical study was carried out. Particle image velocimetry was successfully, developed and applied to determine particle velocity profiles, whereas voidage profiles were determined by digital image analysis. A 3D hard-sphere discrete particle model was used to simulate the flow in a spout-fluid bed. The simulations and experiments showed a similar influence of the background fluidization velocity on the spout behaviour.