Elevated water tanks in an empty condition, though not important in structural design, becomes an important problem in seismic design. The objective of the present research is to investigate the elevated water tanks in empty and in filled conditions and to emphasize the importance of seismic response. Four elevated tanks with various parameters are selected for seismic analysis with the base isolation technique. It is found out that empty tanks are highly vulnerable to earthquake effects, whereas filled tanks can be mitigated by providing base isolation. A simple experimental investigation has also been carried out to validate the analytical results.