The invention relates to a mixing device 1 for integrating into an exhaust pipe 4.1, 4.2 of an internal combustion engine and for intermixing an exhaust gas flow T, which device is formed by a housing 2 comprising a pipe wall 2.1 for guiding the exhaust gas in a main flow direction H, an intermediate wall 3 which at least partially delimits a flow cross section Qs of the housing 2, and by a mixing pipe 5, wherein: the mixing pipe 5 has an injection nozzle 5.1 for an additive to be incorporated, the nozzle being in the region of a first end E1 of said mixing pipe, and the mixing pipe is accommodated, in the region of a second end E2, in the intermediate wall 3; a perforation zone 5.2 having a through-flow cross section Qp is provided at least between the injection nozzle 5.1 and the intermediate wall 3; the intermediate wall 3 and the mixing pipe 5 separate the housing 2 into an inflow sector 2.2 and an outflow sector 2.3; at least 90 % of the gas to be guided from the inflow sector 2.2 to the outflow sector 2.3 can be directed through the perforation zone 5.2; a wedge-shaped flow-directing element 6 having a directing nose 6.1 is provided after the mixing pipe 5, which nose protrudes beyond the pipe wall 2.1 and/or the intermediate wall 3 and by means of which the exhaust gas flow T can be divided into two partial flows T1, T2; and wherein the partial flows T1, T2 can be brought into a counter swirl flow in relation to the main flow direction H.