"The is a culmination of the inclusive government by the political parties in our parliament," clerk of parliament Austin Zvoma said after the swearing in.
The swearing-in came on the eve of Tsvangirai’s maiden address to parliament, when he is expected to lay out his priorities for the new government.
Also sworn in as an MP was Attorney General Johannes Tomana, whose unilateral appointment by Mugabe is being contested by Tsvangirai.
Despite the unity accord, Tomana is overseeing the prosecution of human rights activists and members of Tsvangirai’s Movement for Democratic Change (MDC), including the party’s treasurer Roy Bennett.
The power-sharing government is meant to end nearly a year of political turmoil following disputed elections last March and to stem a stunning economic crisis that has left most of the nation without food and unemployed.
Mugabe said last week that the power-sharing government would be in place for about two years, after which fresh elections will be held.