Reinforced concrete chimneys and natural draught cooling towers are essential components of power plants. As these structures are flexible and prone to earthquakes & wind, their dynamic characteristics are prerequisite for rational and safer design. The paper reports the details of a truncated conical shell element to idealize the chimneys and cooling towers and the development of software for the dynamic response. Vibration characterstics of chimneys and cooling towers have been obtained using the element. The predicted results are compared against the theoretical as well as experimental values available in the literature.