A system (20) of establishing a rapid PTT call setup in a multi-wireless network environment, can include a first wireless network (24 and 26) such as an iDEN network optimized for rapid push-to-talk call setups in typically less than one second and a second wireless network (23 and 27) such as a CDMA wireless network operatively coupled to the first wireless network. The system can further include a communication protocol among an originating mobile subscriber unit (22), a target mobile subscriber unit (28), the first wireless network, and the second wireless network, where the first wireless network and the second wireless network receive a request for a PTT session and the PTT session is set up on the second wireless network using the first wireless network. The system can further include a PTT server (25) operatively coupled to the first wireless network and the second wireless network.