Injection moulding process for producing a syringe with an integrated closure element comprising the following process steps: a) providing an injection moulding tool which comprises a first, a second and a third tool portion, wherein the first tool portion has a mould cavity open at both sides and extending along an axial direction, and wherein the second tool portion has a first injection moulding core and the third tool portion has a second injection moulding core; b) closing the injection moulding tool such that the first tool portion contacts the second and third tool portion, and the first and second injection moulding core each enter the mould cavity of the first tool portion through an opening (5a, 5b) and finally contact each other, as a result of which these tool portions (2, 3, 4) form a first cavity; c) injecting a first plastic material into the first cavity, as a result of which a hollow cylindrical syringe body is formed with an end region at its distal end, wherein the end region has an attachment element, provided with an inner thread, and a hollow cylindrical end piece which is at least partially bordered by the attachment element; d) cooling the tool portions (2, 3, 4), as a result of which the syringe body cools and hardens; e) bringing the first tool portion into contact with a fourth tool portion provided with a mould cavity closed at one end, as a result of which a second cavity is formed at the distal end of the syringe body; f) injecting a second plastic material into the second cavity, as a result of which the closure element is integrally formed on the attachment element, wherein the first and the second plastic material do not enter into a cohesive connection. a) providing an injection moulding tool which comprises a first, a second and a third tool portion, wherein the first tool portion has a mould cavity open at both sides and extending along an axial direction, and wherein the second tool portion has a first injection moulding core and the third tool portion has a second injection moulding core; b) closing the injection moulding tool such that the first tool portion contacts the second and third tool portion, and the first and second injection moulding core each enter the mould cavity of the first tool portion through an opening (5a, 5b) and finally contact each other, as a result of which these tool portions (2, 3, 4) form a first cavity; c) injecting a first plastic material into the first cavity, as a result of which a hollow cylindrical syringe body is formed with an end region at its distal end, wherein the end region has an attachment element, provided with an inner thread, and a hollow cylindrical end piece which is at least partially bordered by the attachment element; d) cooling the tool portions (2, 3, 4), as a result of which the syringe body cools and hardens; e) bringing the first tool portion into contact with a fourth tool portion provided with a mould cavity closed at one end, as a result of which a second cavity is formed at the distal end of the syringe body; f) injecting a second plastic material into the second cavity, as a result of which the closure element is integrally formed on the attachment element, wherein the first and the second plastic material do not enter into a cohesive connection.