The National Constituent Assembly voted 149-20, with another 24 members voting "present," in favor of acting Prime Minister Mehdi Jomaa and the rest of the cabinet, Tunisia Live reported.
Replacing the coalition headed by the Islamist Ennahdha Party was a key step in an agreement negotiated last year to end political stalemate. The assembly passed a new constitution Sunday.
Jomaa, 51, an engineer, only became involved in politics after the ouster of President Zine El Abidine Ben Ali in 2011. He became minister for industry last year.
Jomaa told the assembly he interviewed 300 people to fill 28 spots in the cabinet.
Talking to members for the first time as prime minister, he said Tunisia needs to take steps to kick-start its struggling economy.
The Arab Spring began with large street demonstrations in Tunisia. The country, so far, has managed to escape the violence and political turmoil that have hit Egypt and Syria.