Abstract: A ladder guard, when in placed on the front section of a two-section extension ladder, prevents persons from climbing on the ladder, from either the front or back, and reduces the chances of theft by preventing the ladder from being retracted. The ladder guard comprises a unitary, semi-rigid shell having a central panel portion and two channel portions to each side of the panel. The panel is recessed relative to the channels so that the panel may be drawn closely to the rungs. The channels extend around the side rails of the ladder. The shell may have a multiplicity of openings to allow wind to blow through the shell. The ladder guard includes a hook for engaging a rung of the ladder to support the guard, and an adjustable locking means for securely locking the ladder guard to the ladder.