We present experimental results on stabilizing unstable periodic orbits of an autonomous chaos oscillator based on a simple electronic circuit. Control is achieved by applying the difference between the actual and a delayed output signal of the oscillator. The quality of chaos control can be measured via the strength of perturbation. The dependence on the delay time shows a characteristic resonancetype behavior.Since the pioneer work done by Hübler and coworkers [1], controlling chaos has become a fasci nating topic in the field of nonlinear dynamics. In particular, the method introduced by Ott, Grebogi, and Yorke (OGY) [2] develops to an important tool to overcome undesired chaotic behavior in various fields of applications. The key observation is that the typical chaotic attractor embeds an infinite number of un stable periodic orbits of distinct periods Tt. They can be stabilized by an only small, carefully chosen, feed back perturbation applied to some system parameter available for external adjustment. The OGY approach is as follows; At first, one determines some of the unstable low-periodic orbits of the strange attractor by finding the fixed points in the Poincare map of the system. Then the linear transformations close to these points and their dependence on the parameter varia tion have to be reconstructed from experiment. Fi nally, a small time-dependent perturbation is applied to the system, in order to stabilize these already exist ing periodic orbits.The O GY method is a very general one. It does not require any a priori analytical knowledge of the sys tem dynamics and has been successfully applied to various physical experiments including a magnetic ribbon [3], a spin-wave system [4], a chemical system [5], an electric diode [6], laser systems [7], and cardiac systems [8].