This paper deals with the experimental determination of natural frequency and, damping in infilled frames subjected to dynamic loads. The damping in infilled frames though of dry friction type. is expressed as a co-efficient of equivalent viscous damping which is obtained from free vibration and half cycle load tests. The tests were conducted on relatively large size R.C.C. frames bounding brickwork infill with and witoutshear connectors, Loaddeflection curves are obtained from static tests which are subsequently used in assessingthe lateral stiffness of infilled frames prior to their dynamic analysis. An equivalent dynamic model of an infiUed is assumed for computing theoretically the fundamental frequency of the system. The model has an equivalent mass lumped at the girder level. Its lateral-stiffness is determined from the experimentally obtained load-deflection curve and, also from the idealised diagonally braced pin-joined frame. The results of analytical and experimental natural frequencies agree satisfactorily. Damping in infilled frames, with and without shear connectors, as obtained from dynamic tests subjected to oscillations of small amplitude is found to be 6 and 7 percent of critical damping respectively.