Abstract: The retrofit patient call system retrofits onto the preexisting patient call system. The retrofit system includes a wireless patient call unit mounted on a patient using a wristband or strap and a wall unit retrofit mounted near the preexisting patient call system room port. The patient call unit allows the patient to activate a user actuated control coupled to a transmitter which generates a radio frequency (RF) patient call signal. The wall unit receives the RF patient call signal and produces a patient alarm signal which is sent via the preexisting room port and patient call system to a central monitoring station. The wall unit is programmed either to send the patient alarm signal in the same form as the preexisting hard-wired patient call switch or to activate the preexisting room port to generate the alarm. The wall unit may include a reset and a display for other valuable information.