The haemagglutinin-neuraminidase (HN) and fusion protein (F) gene of four avian paramyoviruses serotype 9 (APMV9) recently isolated from wild birds in Italy have been sequenced. A comparison between the sequences of these four isolates and the prototype virus PMV-9/domestic Duck/New York/22/78 revealed significant sequence variation that suggests that different lineages exist among APMV-9 viruses similar to that seen for APMV-1 (Newcastle disease).