A device for controlling the feed of a yarn to a textile machine operating intermittently on the yarn, there being provided elements to sense the tension of the yarn and elements for measuring and modifying its feed speed, all connected to control and regulator elements for the tension and speed parameters, which continuously measure the values of both parameters during the feed of the yarn to the textile machine so as to act on a rotary member in order to modify the tension of the yarn when necessary. The rotary member is movable in a controlled manner in the two opposing directions of rotation to feed the yarn to the textile machine or to rewind it in order to prevent its accumulation in correspondence with the machine, the tension of the yarn fed or rewound being maintained at constant values.