Abstract: An improved mixing passage in a foam fire fighting nozzle, the nozzle having a barrel with a first inlet to receive liquid under pressure and a second inlet to receive additive fluid and having a discharge end for discharging liquid and additive fluid. The additive fluid is communicated from the second inlet to the barrel discharge through a channel and a baffle is structured with said channel to provide a flow path for additive fluid through the baffle. The baffle cooperates with barrel wall portions to shape a relatively smooth annular liquid stream having a cross sectional area that diminishes to a minimum proximate the nozzle discharge. A mixing plate is affixed to the nozzle downstream of the baffle, the mixing plate being adapted together with the baffle to define a mixing passage in which additive distributes itself around 360.degree. and exits into a portion of the shaped liquid stream at the point of minimum cross sectional area.