<p>An intravenous catheter introducing device includes a needle hub (3) inserted into and axially slidable relative to an inner barrel wall surface (221) of a barrel (2). The needle hub (3) holds a needle cannula (5) and permits the cannula (5) to extend forwardly of the barrel (2) for ready use. A catheter connection assembly (4) is detachably sleeved on a front smaller-diameter wall portion (228) of the barrel (2) and permits a tip end (52) of the needle cannula (5) to project forwardly of a tubular catheter (43) of the assembly (4). A releasably retaining member includes a retaining hole (231) formed in a rear larger-diameter wall portion (229) of the barrel (2), and a radially extending engaging peg (33) engageable in the hole (231) . Operation of an actuator (34) mounted on the peg (33) can disengage the peg (33) from the hole (231) so as to permit axial movement of the needle hub (3) for drawing the needle cannula (5) within the barrel (2).</p>
