When a door is open, at a hinge side of the space between the door and door frame a gap appears and this presents an opening into which a young child's hand or fingers can very easily be inserted. The invention provides a cover for this space which can help to reduce risk of injury if the door should be closed accidentally when a child's hand is present. A door safety device comprises a cover for the gap at the hinge side of a door (2) and door frame (4) combination, the cover comprising a strip of a rigid material which is flexible about its major axis, the strip having attachment means at its long edges so that one edge may be secured to the door (2) and the other edge to the door frame (4) of the combination, and the cover including fastener means (13) adjacent to one of its long sides such that the cover may be secured to a second similar cover in order to increase the effective width of the safety device. This can enable a single model of safety device to be adapted to fit ordinary domestic doors and also doors which open through wider angles such as up to 180°.