Systems and techniques for identifying the presence of a jamming signal impairing the operation of an RFID reader. An RFID reader includes a signal strength detector that detects and measures the signal strength of signals within a prescribed frequency range typical of that used by RFID devices. If a signal within the frequency range and exceeding a predetermined maximum strength is detected, the reader identifies the presence of a jamming signal impairing the proper operation of the reader. The reader takes appropriate action upon identification of a jamming signal, for example issuing a local alert or alarm, or sending a message to a central security station, which may then take appropriate action in response to the message, such as alerting appropriate personnel, sounding alarms or securing exits.