A self-checkout kiosk enables a patron to purchase product carrying a Radio Frequency Identification (RFID} tag. The kiosk includes a frame defining a portal through which the patron must exit from a vending area in which product is stored and available for purchase. A card reader, bill acceptor and a computer monitor adjacent the portal enables the patron to complete a purchase transaction prior to exiting the vending area through the portal. The frame carries RFID reading antennas for detecting product being transferred through the portal. A security system responds to transfer of product through the portal without completion of a purchase transaction.