Abstract: An adapter for sterilizing a needleless connector that has interior and exterior surfaces. The adapter includes a proximal portion that is coupleable in electromagnetic radiation receiving communication with an electromagnetic radiation source and a cavity portion that is coupleable with the needleless connector and that is shaped to receive at least a portion of the needleless connector. The proximal portion and the cavity portion are made from a translucent material so that electromagnetic radiation from the electromagnetic radiation source can, upon operation, propagate through and be refracted by the translucent material to sterilize both the interior and the exterior surfaces of the needleless connector.