Abstract NiTi multilayers with a composition of Ni 45Ti 55 and composition-modulations lengths ranging from 10 nm to 40 nm were annealed at 533 K up to approximately 64 h and studied with in situ electrical resistivity measurements. The resistivity was also measured at 77 K, 293 K and 303 K before and after the anneals at 533 K. The temperature coefficient of the resistivity at the annealing temperature was determined as a function of annealing time by correlating temperature and resistivity noise. Specimens were characterized before and after annealing by X-ray diffraction analysis. The temperature coefficient of the resistivity changed sign from positive to negative on annealing, demonstrating that amorphization takes place. As a result of amorphization the resistivity increased on annealing. The kinetics of the resistivity change for small composition-modulation lengths indicate that amorphization takes place along the interfaces and along the grain boundaries in the sublayers.