• Human parainfluenza viruses (hPIVs) cause significant disease in infants, the elderly and immunocompromised persons. • Haemagglutinin-neuraminidase (HN) has multiple roles in the hPIV lifecycle, making it an attractive antiviral drug target. • Computational modelling and structure-based inhibitor studies have enhanced the development of potent hPIV3 HN inhibitors. • Current inhibitor strategies targeting HN are primarily based on sialic acid analogues. • Identification of new targets and inhibitor scaffolds could prove worthwhile in the fight against hPIVs.