Nickel-induced recrystallization of tungsten wire was investigated using a lamp-grade tungsten wire of 1mm diameter having a 40 μm thick layer of nickel formed by electrolytic plating. The wire was exposed to hot argon environments of 1200 to 1300°C and the resulting microstructural changes were examined in correlation with the distribution of nickel atoms detected by electron probe microanalysis (EPMA). The examination revealed two different microstructural states corresponding to primary and secondary recrystallization. In the primary-recrystallized region extending inwards from the wire periphery, the presence of nickel atoms was detected by EPMA. These grains had the 110 direction prefered orientation. The secondary recrystallization was characterized by a coarse grain structure. Nickel atoms were enriched in and around the grain boundaries. Although the high temperature strength of the wire was little affected by the recrystallizations, the ductile brittle transition temperature (DBTT) increased. While DBTT was as low as 200°C for the nickel-free wire even after heat treatment at 1300°C for 100 h, it was around 400°C and 900°C for the nickel-coated wire after the primary and the secondary recrystallization, respectively.