An improved method and apparatus for introducing a flexible member into the epidural space of the spinal column of a patient employing an introducer assembly for achieving access to the epidural space. The introducer assembly includes an epidural needle assembly, including an elongated needle having a side opening at its distal tip, a hub at its proximal tip and a lumen extending therebetween, and a stylet removable insertable within the lumen of said needle through said hub and having a beveled tip and a hub. The distal tip may be curved in the direction of the side opening when unrestrained by the stylet. The introducer assembly has a locking mechanism which preferably includes a lug extending from the side of the needle hub and an L-shaped cut-out in the side of the stylet hub for receiving the lug therein and allowing its rotation 90.degree. to effect a bayonette-style locking of the two hubs.