Recombinant paramyxoviruses including a viral genome encoding a heterologous gene are provided. In several embodiments, the recombinant paramyxovirus is a recombinant parainfluenza virus, such as a recombinant PIV3 including a viral genome encoding a heterologous respiratory syncytial virus F ectodomain linked to the transmembrane domain and the cytoplasmic tail of the F protein from the PIV3. Nucleic acid molecules including the genome of a recombinant paramyxoviruses are also provided. The recombinant viruses may advantageously be used in vaccine formulations, such as for vaccines against parainfluenza virus and respiratory syncytial virus.