A physical map was generated for the fowlpox virus Chick-N-Pox vaccine strain DNA genome forEcoRI,BamHI,NcoI, andPstI. The gel profiles resulting fromEcoRI,BamHI,BglII,NcoI,StyI,PstI, andPvuII digestions were analyzed by agarose and polyacrylamide gel electrophoresis. The size of the fowlpox virus genome was estimated from these digests to be 289–301 kb. Replication of fowlpox virus DNA in QT-35 cells was followed and indicated that viral DNA replication initiated at 6–8 h postinfection in these cells.Key words: physical mapping, fowlpox virus, QT-35 cells, DNA replication.