The inverse problem we consider in this paper seeks, based on the equivalent source method, to determine the shape of perfectly conducting cylinders from the scattered farfield data obtained by using several incident waves. When incident waves of different frequencies are used, the shape of the scatterer can be reconstructed by employing only a few number of observation points. In the reconstruction problem, to determine the shape of the scatterer, the conjugate gradients method is applied. The general approach is applicable to cylindrical scatterers of arbitrary shape. Results of numerical simulations are presented to support the suggested approach.