Abstract A fluid-filled cylindrical shell comprising a wall joint is investigated by using the concept of vibrational power flow. The power flow in the contained fluid and in the shell wall of this fluid-filled elastic cylindrical shell is studied. The transmission loss of vibrational power flow through the wall joint is studied and an analysis of power flow transmission and reflection at the joint in fluid-filled shells is presented. Material stiffness of the joint and frequency are two important factors that are found to strongly influence the results. It is hoped that the analysis will shed some light on the control of vibrational propagation in shells filled with fluid.