Abstract: The device (1) is provided for introducing an elastic indwelling cannula (15) with a rigid puncture cannula located therein, into a blood vessel of a human or animal body. It comprises holders (8, 13) for the cannulas (9, 15) to be introduced as well as a locating means for locating the vessel and for aligning the cannulas (9, 15) to the vessel. The holders (8, 13) are in each case fastened on the device by way of a guide (10) and displaceably mounted in the introduction direction as well as in the counter direction. They may be traversed electromotorically independently of one another along the guides. The control of the electromotors is effected in dependence on the signals of the locating means so that the complete introduction procedure may be automatically controlled up to the retraction of the puncture cannula.