Abstract: A fire hose clamp that comprises a U-shaped guide structure for slidably supporting a movable jaw; a manual rotary screw extends from the movable jaw through a nut in the central wall of the U-shaped structure, whereby rotation of the screw moves the jaw along the guide structure. A stationary jaw is arranged in the path of the movable jaw, such that the two jaws exert a squeezing action on a fire hose extending through the jaw space; the hose fabric is flattened to shut off the flow of water through the hose. Preferably the jaws have curved surfaces that tend to iron away any creases or bulges in the hose fabric during the hose-squeezing operation, thereby assuring a more consistent water shut-off action.