A marker delivery device is configured for deploying a tissue marker. The marker delivery device includes a handle having a chamber, and a cannula. According to one aspect, the cannula has a flexible portion formed by a slot arrangement having of a plurality of spaced-apart substantially parallel peripheral slots extending through the side wall of the cannula to the lumen. A marker introducer rod is movably disposed in the lumen of the cannula for deploying the mark, and has a flexible region that corresponds to the flexible portion of the cannula. According to another aspect, a retraction mechanism is mounted to the handle and is configured to facilitate a complete retraction of both the cannula and the marker introducer rod into the chamber of the housing of the handle upon an actuation of the retraction mechanism.