The effects of particle size (d(p)) and superficial gas velocity (U-g) on the transport disengaging height (TDH) of iron ore particles were determined for a fluidized bed (i.d.: 0.11 m; height: 2 m). The entrainment rates of iron ore particles in the size range 0.063-1.00 mm in the height direction of the bed were measured by using an isokinetic sampling probe, and they were used to determine the TDH for different values of d(p) and U-g. The entrainment rate decreases exponentially with an increase in the freeboard height and particle size but increases with the gas velocity. The TDH increases with the gas velocity, but the TDH values are much less than values predicted from correlations in previous studies. The effect of particle size on the TDH is more pronounced than the effect of gas velocity and therefore, the TDH can be predicted by considering Froude and Reynolds numbers.