Experimental measurements on the axial dispersion of fluid in an oscillatory baffled tube that is operated continuously were studied. Two models, the continuous stirred tank with feedback and the plug flow with axial dispersion, were used to analyze the residence-time distributions and determine the axial dispersion for this system. The effect of the density of tracer solution, the tracer injection position, and the tracer injection time on the axial dispersion was explored. It was found that the axial dispersion was sensitive to the changes in the density of tracer solution, but insensitive to the tracer injection position and injection time. A correlation linking the axial dispersion with the energy dissipation in the system both in the absence and presence of fluid oscillation was established. The Isotropic Turbulence Theory was applied, and for the first time the mixing length in the system was evaluated and compared with that of other devices.