I will discuss the detection and dynamical properties of circumbinary extrasolar planetary systems. I will pay special attention to the detection of circumbinary companions using the light-travel time effect and highlight some problems of proposed systems discovered from ground-based observations concerning their orbital stability. In addition, I will briefly review the latest discoveries of circumbinary planets detected by the Kepler space telescope and present my latest research on the Kepler-47 multi-planet system concerning the prediction of a third planet in that system.