It has been established that very short patch (VSP) mismatch repair, depending in Escherichia coli on MutL, MutS and Dcm functions, is responsible for the hyper-recombinogenic effect of a class of genetic markers. We show that VSP repair requires the presence of the complete DNA polymerase I enzyme. The absence of endonuclease activities involved in the repair of base-loss sites, Nth, Nfo and Xth, does not affect VSP repair. Implications for the mechanism of the VSP repair are discussed.