The device for detecting breakage of leno threads in leno selvedge devices on looms, the leno selvedge forming device being provided with at least two arms for guiding at least two leno threads, the leno threads being twistable together by virtue of the rotation of the arms, the device (12, 13, 14, 14a) for detecting thread breakage being provided with a facility (13, 14) for determining the natural oscillations of the arms (12) and a loom, more specifically with heald frames, with at least one leno device which is reversible in its direction of rotation and with a facility for detecting breakage of the leno threads, the device for detecting thread breakage being arranged in the front shed (V), more specifically between the leno device (10) and the heald frames (20).