We investigated adeno-associated virus (AAV) vector-based suicide gene therapy toward experimental human glioma transplanted in the brain of nude mice by intratumoral injectioin of AAVvector carrying herpes simplex thymidine kinase (HS-tk) and intraperitoneal administration of ganciclovir (GCV). Single treatment of HS-tk/GCV significantly inhibited the growth of the tumor and complete regression can be obtained by its multiple treatments.