An RFID assembly includes a base having a peripheral wall, an RFID inlay including an RFID tag disposed within the peripheral wall, and a disk having a periphery engaged by the peripheral wall to capture the inlay between the base and the disk within the peripheral wall. One of the base and the disk has external fingers for releasably securing the assembly to a support structure, such as a projection on a mold core for disposition within a mold cavity to mold a container preform around the mold core within which the RFID assembly is embedded. The container preform can be blow molded into a hollow plastic container within which the RFID assembly is embedded. The projection preferably is on an end of the mold core, so that the RFID assembly is embedded in an end wall of the preform and a bottom wall of the container.