Abstract: A ladder stabilizer (32, 232) suitable for use with a ladder (30, 230). A preferred stabilizer (32) includes an elongate telescoping stabilizer member (46) which is pivotally connected to the apex of the ladder (30). The inner submember (50) is pivotally attached to the apex of ladder (30). The outer submember (52) of the stabilizer (46) is operatively connected to pivotally opposing uprights (34) and (36) such that the stabilizer (32) enjoys a three point connection to the ladder (30) to maximize the rigidity of the ladder/ladder stabilizer combination. Preferred embodiments include lock assemblies (62, 81, 82). Release of the lock assemblies allows the stabilizer to be laterally and transversely adjusted. When the lock assemblies are activated, the stabilizer (46) is locked relative to the ladder (30) thereby stabilizing the ladder regardless of the ground conditions or the presence of a wall, for example.