The burr hole plug comprises a plug base configured for being mounted around a burr hole, and having an aperture through which an elongated medical device exiting the burr hole may pass. The burr hole plug further comprises a retainer configured for being mounted within the plug base aperture. The retainer includes a retainer support, a slot formed in the retainer support for receiving the medical device, and a clamping mechanism having a clamping bar and a flange slidably engaged with the retainer support to laterally slide the clamping bar to secure the medical device. A method comprises introducing the medical device through the burr hole, mounting the plug base around the burr hole, mounting the retainer within the plug base aperture, receiving the medical device into the slot, and sliding the slidable flange relative to the retainer support to laterally slide to secure the medical device.