Abstract: An entanglement tester, for testing the degree of entanglement of the yarns such as jet-entangled, yarn, is provided. A complex yarn path is provided, having sections arranged at angles to each other, and a measuring device is provided which may be displaced by shortening the yarn path. Means are provided for inserting a pin or needle into and through the yarn, guiding the yarn onto and off of the pin by using pivoting or sliding guides that are worked by yarn tension, and the yarn is displaced in a manner to shorten the yarn path, thus displacing the measuring device until a point of entanglement is reached. The distance between point of insertion and point of entanglement may be read out, and the measuring process repeated many times without painstaking hand guiding operations.