A self-closing antiseptic plaster (1) for puncturing blood vessels, muscle tissue, tissue, skin, organs (biopsy) or bone marrow is puncturable by cannulas, needles or the like. It has a backing layer (2), a sealing layer (5) made of a material having an elastic restoring force and a skin adhesive layer (3) applied to the underside U of the backing layer (2), said the sealing layer being applied to the backing layer (2) by means of an adhesive layer (4). The backing layer (2) is usually thin. The backing layer (2), the sealing layer (5), the adhesive layer (4) and the skin adhesive layer (3) are transparent or approximately transparent in the entire area or at least in a superimposed partial area. The backing layer (2) and the sealing layer (5) are made of thin and soft materials so that any puncture site is visible and/or palpable through the self-closing antiseptic plaster (1). The advantages include the fact that the antiseptic state at the puncture site is preserved before, during and after the puncturing.