A method and device for controlling the feed of an elastomeric yarn (11), of known elastic characteristics, withdrawn from a bobbin (B) and fed to a textile machine (10) such as a knitting machine, a stocking machine, a bobbin winder or other textile machine, the yarn possessing an intrinsic elasticity and being fed to the machine with an intrinsic speed, there being provided elements (18) for sensing the tension of the yarn (11) and elements (3, 12) for measuring and modifying this speed, both associated with a single body (2) of the device (1) and both connected to elements (20) for controlling and regulating the tension and speed parameters; elements for compensating the variation in the elongation of the yarn being provided to maintain the diameter and the quantity of the yarn fed to the textile machine constant.