The effect of stresses is known to modify the magnetic properties in magnetostrictive amorphous wires. A comparative study of the giant magnetoimpedance (GMI) for amorphous wires with compositions Fe77.5Si7.5B15, Co72.5Si12.5B15 and Co68.15Fe4.35Si12.55B15 and positive (30 × 10-6), negative (-2 × 10-6) and vanishing (0.1 × 10-6) magnetostriction have been studied. The influence of torsional stress on hysteresis loops and GMI is also reported. Modifications of GMI response are ascribed to the magnetoelastic anisotropy induced by torsion. © 2002 Elsevier Science B.V. All rights reserved.