Infection of WI-38 human fibroblasts with varicella-zoster virus led to the stimulation of host cell DNA polymerase synthesis and induction of a new virus-specific DNA polymerase. This virus-induced DNA polymerase was partially purified and separated from host cell enzymes by DEAE-cellulose and phosphocellulose column chromatographies. This virus-induced enzyme could be distinguished from host cell enzyme by its chromatographic behavior, template specificity, and its requirement of salt for maximal activity. The enzyme could efficiently use poly(dC).oligo(dG)12-18 as well as poly(dA).oligo(dT)12-18 as template-primers. It required Mg2+ for maximal polymerization activity and was sensitive to phosphonoacetic acid, to which host alpha- and beta-DNA polymerase were relatively resistant. In addition, this induced DNA polymerase activity was enhanced by adding 60 mM (NH4)2SO4 to the reaction mixture.