Arrangement for introducing a liquid medium into exhaust gases from a combustion engine, having a mixing duct, an injector for injecting the liquid medium into the mixing duct, and an inlet duct situated upstream of the mixing duct. The inlet duct has a first duct section which is annular in cross-section and a second duct section which is annular in cross-section. The second duct section is situated downstream of the first duct section and surrounds the mixing duct. The first duct section surrounds the second duct section. The mixing duct further has a flow reversal section via which an annular outlet of the first duct section is connected to an annular inlet of the second duct section and which is configured to reverse the direction of flow of the exhaust gases flowing through the inlet duct, to flow through the second duct section in a direction opposite to that of the exhaust gases in the first duct section.