A device is provided for injection of a liquid agent, such as fuel or reducing agent, into the exhaust line from a combustion engine. The device (1) has a nozzle arrangement (20) having a nozzle head (21), from which the liquid agent is injectable into the exhaust line. The nozzle arrangement (20) has a first conduit (22) leading to the nozzle head (21) for supply of compressed gas, preferably in the form of compressed air, to the nozzle head, and a second conduit (23) leading to the nozzle head (21) for supply of the liquid agent to the nozzle head. The nozzle head (21) is provided with at least one outlet opening (24) connected to the first conduit (22) and to the second conduit (23), through which outlet opening the liquid agent is injectable into the exhaust line under atomization thereof after mixing with compressed gas in a mixing zone (25) inside the nozzle head.