Abstract: A blood sampling device for introducing a blood sample into a vacuum tube including a pierceable stopper, the device comprising: a tubular body including a side wall provided with at least one longitudinal slot ending in rear and front enlargements, and a front transverse wall provided with an orifice and a cannula having a front part and a rear part extending on either side of a side housed in the tubular body and cooperating with the longitudinal slot, the slide being displaceable between a rear end position in which it is located in the rear enlargement of the slot while the front and rear parts of the cannula are situated inside the tubular body, and a front end position in which it is locked in the front enlargement of the slot while the front part of the cannula passes through the orifice in the transverse wall of the tubular body and protrudes from the latter for the purpose of implanting it in a sampling zone and introducing a blood sample into the vacuum tube, after the latter has been placed in the