The invention relates to a wall-mountable hand dryer of the type which uses an air-knife to wipe the water from a user's hand. In accordance with the invention, the hand dryer is configured to have a maximum depth, front-to-back, of less than 150 mm when it is surface-mounted on—not recessed within—the wall. The air-knife is discharged downwardly through one or more discharge apertures on the dryer. These discharge apertures are configured so that the air-knife is discharged in front of the wall or a rear part of the dryer, and is discharged forwards towards the user at a downward angle. The downward angle of the air-knife is such that the air-knife projects to a distance of at least 75 mm in front of the wall or, as the case may be, in front of the rear part of the dryer.