A delivery system for an expandable filter device includes a dual lumen delivery sheath which has a lumen for receiving the expandable filter device and a lumen for receiving a primary guide wire. The primary guide wire is utilized to place the delivery sheath and expandable filter into the desired region of the patient's vasculature via an over-the-wire or rapid-exchange arrangement. The delivery sheath can be protracted over the expandable filter device to allow the filter to be deployed within the patient's vasculature at the desired location. The delivery system can be embodied in an alternative design in which the primary guide wire extends through a guide wire lumen located in an obturator which forms part of the expandable filter device. Again, the primary guide wire is utilized to maneuver the filter device into the desired area via an over-the-wire arrangement. A slit extending longitudinally along the length of the sheath facilitates the removal of the guide wire and delivery sheath from the patient's vasculature.