Few reports describe the reactivation of latent herpes simplex virus causing encephalitis (HSVE) in patients undergoing brain radiation therapy and a concomitant steroid regimen. The role for steroid use in the treatment of patients with HSVE has not been fully elucidated. We report the case of a female patient immunosuppressed by steroids and brain radiation who developed HSVE and responded to acyclovir and dexamethasone.