Said Darwazeh, the health minister, said the 31 year old had been taken to hospital on Thursday after suffering severe breathing problems, three days after he returned from the Fayoum region in Egypt where people had been in contact with infected poultry.
"He tested positive for H5N1 virus on Friday but his condition is good and (he is) getting treatment and we are coordinating with the Egyptian authorities," Darwazeh said.
He said tests showed there were no other cases, although Adel Belbissi, a senior ministry official, said six people who shared an apartment with the man had also been admitted to hospital for observation.
The man had lived in Jordan for three years. "He was infected in his (home) country. He and his family in the village of al-Jaafra in Fayoum had slaughtered many chickens after a lot of sick poultry and birds died," Darwazeh added.
Jordan's neighbours Iraq and Egypt have reported infected poultry and human deaths from bird flu.
Darwazeh said the country was braced for new outbreaks. "We are prepared for the possibility of new outbreaks especially since we are close to infected areas," he said, adding that samples had been sent to the World Health Organisation.
Authorities said they were giving out anti-viral drugs in the southern city of Karak where the labourer worked. Those who had come into contact with him and travellers who arrived with him at the port of Aqaba were also being tested for the virus.
Egypt has reported bird flu infections in five people in recent weeks, two of whom died.
Hundreds of thousands of Egyptians live and work in Jordan and travel with few restrictions. Officials said they would try to screen the thousands of workers who arrive from Egypt daily.