This paper presents an integrated smart label for tracing food information and monitoring its preservation conditions. The system includes humidity, temperature, and light intensity sensors with the respective interface circuits, an A/D converter, and a 13.56-MHz RFID transponder for transmitting and receiving data, as well as for gathering from an external reader the energy for recharging the on-board microbattery and powering the transmitter. The proposed systems, designed in a 0.18-mum CMOS technology, achieves in simulation the required performance, in terms of functionality, accuracy, and power consumption.