The stochastic method of Monte Carlo simulation is used to predict the hydrodynamic characteristics of a liquid-solid inverse fluidized bed for various particle sizes and densities. Pressure drop, bed voidage, and minimum fluidization velocity under steady-state conditions are predicted. Unsteady-state bed expansion/contraction for a step change in liquid flow rate is also simulated. To validate the simulation, experiments are conducted to measure the different hydrodynamic variables such as pressure drop, bed voidage, and minimum fluidization velocity under steady-state conditions and unsteady-state bed expansion/contraction. The predicted values of the hydrodynamic variables compare satisfactorily with the experimental data under both steady- and unsteady-state conditions.