The induction of DNA polymerase of herpes simplex virus type 2 in HeLa cells was inhibited by 2-mercapto-1-(beta-4-pyridethyl)benzimidazole added at an early time after infection. However, the inhibitory effect was easily released by removal of the inhibitor. Since the drug disorganizes nucleolar structure and prevents its function in HeLa cells in a reversible manner, it is possible that nucleoli are involved in the induction of DNA polymerase of this virus.