The systematic experimental investigation on the effect of baffle free area, baffle spacing and baffle thickness on mixing time in batch oscillatory baffled columns is reported where the form of oscillation can be achieved by either pulsing the fluid from the base of the column or oscillating the baffles at the top. Local concentration profiles are measured using conductivity probes at two locations along each column. The mixing time was determined based on the equilibrium concentration format. The experimental results have identified the optimal geometrical parameters for obtaining the lowest mixing times in such columns.