An investigation on oscillatory flow in a baffled column was carried out to determine the effects of various operating parameters on interstage backmixing. Among parameters studied in this work were liquid flow rate, liquid viscosity, oscillation frequency, and oscillation amplitude. The results of this study indicated that the interstage backmixing had a maximum value under nonflow condition but decreased with liquid flow rate. Lower backmixing rate was observed in liquids with higher viscosity. Oscillation frequency and amplitude are the dominating factors that increase backmixing as these factors increase.