Active constrained layer damping in cylindrical shells of revolution are studied. A three noded, isoparametric, multilayered, semianalytical finite element is developed and used. A layerwise theory is assumed for the thickness variation of the displacements and electric potential. The electrodes on the sensors/actuators are spatially shaped to reduce spillover between circumferential modes. The effect of axial and circumferential mode numbers, feedback factor, length to radius ratio, radius to thickness ratio of the shell, percentage area of the shell covered with collocated piezoelectric sensors/actuators and the axial location of the collocated sensors/actuators, on the damping ratio of the cylindrical shells of revolution are studied. A comparison is also made between the active constrained layer damping and the conventional passive constrained layer damping treatments for the class of shells considered. © 2001 Elsevier Science Ltd.