Protein and genomic studies of a previously uncharacterized porcine paramyxovirus (designated LPMV) confirmed that it was a member of the paramyxovirus genus. The nucleotide sequences and deduced amino acids of the complete P-gene, M-gene, F-gene and HN-gene as well as the intergenic sequences have been determined. Comparative sequence analysis of the M-gene of LPMV revealed the closest relationship of LPMV was to human mumps virus with a homology of 46% and 55% at the amino acid and nucleotide levels respectively. The P-gene of LPMV is transcribed to V protein mRNA and by editing of the gene to the P protein mRNA. The LPMV P-gene has the coding capacity for an additional protein of 126 amino acids, a C protein.