In this article, we present a computational approach to the imaging of a partially immersed perfectly conducting cylinder by the steady-state genetic algorithm (GA). A conducting cylindrical section of unknown shape scatters the incident transverse electric wave in free space, while the scattered field is recorded outside. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived, and the imaging problem is reformulated into an optimization problem. An improved steady-state GA is employed to search for the global extreme solution. Numerical results demonstrate that, even when the initial guess is far away from the exact one, good reconstruction can be obtained.