With more than 5.100 representatives observed in electron microscopy, tailed bacteriophages represent the largest viral group known (ACKERMANN et al. 2000), but only a few phages in the genus Fusobacterium have been described until now. Nine chloroform resistant phages with different plaque morphology and specific for F. varium could be isolated from domestic sewages. Electron microscopy revealed three different morphotypes. Two phages belonged to the morphological group of the Myoviridae with a long contractile tail, representing a new morphotype with specificity for F. varium. In addition other phages with morphotypes according to the Siphoviridae or Podoviridae could be isolated. The host ranges of the phages were tested by the spot test on soft agar overlays. All strains of F. varium were lysed by one ore more of these phages. No complete identical type of lysis pattern could be observed. One strain (MLU 91-2641/1) was lysed by all nine phages, indicating its potential use as indicator or propagation strain, e.g. for the detection of a viral-faecal contamination in water samples. Together, all of the tested strains of F.varium were lysed by the phages fv Na5 and fv 83-554/3/3, therefore this phages could be useful as a "diagnostic tool" for identification of the species Fusobacterium varium. It is remarkable that both indol-negative and -positive strains of F. varium were lysed by all the phages, indicating a not uniform indol-production in F. varium. The further characterization of the phages was done by analysis of the structural proteins and the nucleic acids by means of PAGE and separation on agarose gels after digestion with restriction endonucleases, respectively. There was no complete match between the tested phages in all properties; nevertheless the phages seemed to be closely related within the same morphotype.