The deceased has been identified as Rama Shankar Mandal, 30, of Lalparsa in Parsa district, according to the police.
Mandal was shot dead in front of the main gate of the state owned Agricultural Input Corporation in Birgunj.
He sustained three bullet injuries in his chest.
According to the police, the assailants came on a motorbike with an Indian number plate and fled the scene after opening fire at Mandal at around 11:30 am (local time) today.
The police have launched a search operation following the incident.
The motive behind the shootout is not yet known.