One of medical RFID system uses 13.56MHz as a carrier frequency. This type of RFID tag is used identification of patient, staff, medical equipments and so on. On the other hand, a new technique for LAN is developed. It is named PLC (Power Line Communication). In the system, AC power supply line is used for communication. The signal is transmitted by SW band carrier. However, the PLC signal is very noisy. The signal may affect some information equipments that are located near by AC power supply line. Medical use 13.56 MHz RFID systems also uses same band. Identification of the 13.56 MHz medical RFID tags may be affected by PLC. On the other hand, electric lamp shaped fluorescent tube is also noisy. In this study noise level of PLC and electric lamp shaped fluorescent tube are analyzed for risk management of medical RFID system. In the result of the experiment, it is recognized that the noise level of PLC and electric lamp shaped fluorescent tube are critical for medical RFID system.