Ninety-two parliamentarians voted in favour, 14 against and two abstained. Twenty deputies deputies were absent.
Following the vote, Seniora was to depart on his first official visit abroad Sunday to Damascus to improve relations with Lebanon’s neighbour.
“I will be going with God’s willing to Damascus on Sunday to discuss future relations based on mutual respect and cooperation,” Seniora told deputies.
The main anti-Damascus alliance that nominated Seniora has an eight-seat majority in the 128-member legislature following parliamentary elections in May and June.
Seniora’s cabinet is the first elected government since Syrian troops withdrew from Lebanon in April.
His cabinet also includes a minister from the Shiite Moslem fundamentalist movement Hezbollah, which the United States considers a terrorist organization.
In New York, United Nations Secretary General Kofi Annan welcomed the vote of confidence for the new government and its reform agenda, a spokesman said.
Seniora presented a reform package Thursday to parliament, pledging to focus on national reconciliation and democracy.
The three-day parliamentary debate centred on loosening Syria’s crackdown on Lebanese commercial cross-border transit, the future of Hezbollah, which the United Nations has called on to disarm, and the plight of Lebanese refugees in Israel.
Annan offered U.N. support for the new government “in meeting the challenges ahead in the best interest of the people of Lebanon” and full implementation of U.N. resolutions on disarming of militias.
The debate between Hezbollah and members of the Free Patriotic Current, led by Christian firebrand former general Michel Aoun, over amnesty for Lebanese who worked with Israel during 22 years of occupation of southern Lebanon had become heated.
Aoun’s 21-member bloc did not vote in favour of Seniora’s government, as well as a handful of pro-Syrian legislators.
Seniora, 62, is a former finance minister and close ally of predecessor Rafik Hariri, who was killed in a bomb blast in February in Beirut that was widely blamed on Syria and its allies in Lebanon.
Seniora has called for “healthy, privileged and solid relations” with Lebanon’s former political masters.
He is due to meet Syrian President Bashar al-Assad and Prime Minister Mohammad Naji Otri during his visit.