This study describes the localisation of Hsps 70 and 90 in BHK-21 cells during Theiler's murine encephalomyelitis virus (TMEV) infection. In addition, the effect of Hsp90 inhibitors novobiocin and geldanamycin on the development of CPE and production of non-structural protein 2C was monitored over a 48 hour period. It is suggested that these chaperones play an important role in the lifecycle of TMEV.