Today the Chamber of Deputies is set to give him the vote of confidence he needs to start work, and the Senate is expected to follow suit early next week. The volatile right-wing coalition led by his predecessor, Silvio Berlusconi, which had threatened to scupper his chances, announced yesterday that it would merely abstain. With "yes" votes already assured from former Communist and Christian Democrat parties, Mr Dini should be home and dry.
But the road to power has been far from easy. Mr Dini has found himself rejected by his allies and championed by his adversaries. He represents the values of the conservative right and yet will reap most of his support from the centre-left.
Strangest of all, the career banker has become a figurehead for democracy, even though he has never held an elected post and his job as prime minister is to slow down, not speed up, the timetable for fresh elections. Such paradoxes are the product of thedeep crisis at the heart of Italy's governing class.
Mr Dini had served as Mr Berlusconi's treasury minister and was a loyal follower of the media tycoon's Freedom Alliance. It was Mr Berlusconi who proposed him as his successor when President Oscar Luigi Scalfaro insisted on a stop-gap figure to attend tourgent business before new elections.
But Mr Berlusconi and his reformed neo-Fascist allies turned against Mr Dini, fearing he might not call elections as early as they hoped.
Mr Dini's main supporters have thus ended up being the PDS, the former Communist party which only two months ago was organising successful demonstrations against cutbacks on state pensions proposed by Mr Dini himself.
The PDS leader, Massimo d'Alema, undaunted by the fact that pension reforms are back on Mr Dini's agenda, has explained the volte-face as a defence of democratic values against an attempt at "subversion" by Mr Berlusconi's friends.
Such contradictory positions are unlikely to hold and Mr Dini will hope he can complete budgetary and electoral reform before his support crumbles. Yesterday the tide was pulling towards him, with 50 members of Mr Berlusconi's Forza Italia movement voicing tacit support.