A physical map of the chromosome of Campylobacter fetus subsp. fetus was constructed by using pulsed-field gel electrophoresis of restriction fragments generated by Sal I, SmaI and NotI. Digestion of the type strain ATCC 27374 with these restriction endonucleases resulted in generating 4–14 fragments. The order of the fragments was deduced from hybridization of these restriction fragments to Southern blots of pulsed-field gel electrophoresis gels generated by the other two enzymes. The estimated genome size was 1160 kb. The position of several homologous and heterologous genes was determined on the circular map. These included the 2.8-kb sapA gene, encoding the 97-kDa surface array protein. Three copies of ribosomal RNA genes for which the 16S, 23S and 5S rRNA appeared to be located in close proximity in each of the three regions. The RNA polymerase genes rpoA, rpoB, and rpoD were mapped and appeared to be situated close together in one region. The flagellin genes (flaAB) of C. jejuni and the gyrase genes gyrA and gyrB of C. perfringens and Bacillus subtilis, respectively, were used to identify the locations of flaAB, the gyrA and the gyrB genes on the ATCC 27374 chromosome.