The patient is a man who travelled on the same plane with a little girl admitted on June 13 at the "Victor Babes" infectious diseases hospital in Timisoara, western Romania. He was admitted to the same hospital and is receiving treatment.
Nine of the AH1N1 flu patients in the country have already been released from hospital.
Last week, the World Health Organization officially declared the swine flu a pandemic, raising the alert to the highest level of six.
Also last week, Romanian health minister Ion Bazac underscored Romania does not register cases of widespread infections, adding that, apart from basic hygienic rules, Romanians need not make any changes in their daily lives.
Bazac mentioned masks will be distributed to border police and doctors who come in contact with people coming in from some of the states most affected by the new virus, such as the U.S., Canada and Mexico.