At the end of a lengthy session on Tuesday that lasted over 15 hours, senators voted 59 to 21 to approve the trial, surpassing the 41 votes needed for the trial to commence, Xinhua news agency reported.
Rousseff was accused of committing fiscal fraud while trying to balance the 2014 budget. She has not yet made any comments on the Senate's decision.
During the session, senators pressed their respective points for and against Rousseff's impeachment in lengthy speeches.
The opposition said the President committed a crime of financial irresponsibility by resorting to fiscal manoeuvres to balance the budget, which is written in the country's law as punishable by impeachment.
They blamed Rousseff's decisions for the current state of the Brazilian economy which is currently facing a recession with no end in sight while unemployment and inflation are on the rise.
Rousseff's supporters said the fiscal maneuvres to which she resorted did not constitute crime of financial irresponsibility and were perfectly legal decisions at the time.
The president herself denounced the impeachment process as a plot of the office of Vice President Michel Temer, whose difficult relationship with Rousseff turned into full-blown hostility and culminated in the dissolution of the alliance between Rousseff's Workers' Party and Temer's Brazilian Democratic Movement Party earlier this year.
Temer has been in office since May, when Rousseff was suspended by the Senate. Though his administration is in theory temporary, it took measures of a much more permanent nature.
The interim President's administration carried out measures that would damage the Workers' Party, such as labour rights and social programmes.
In addition, there was a discussion about corruption. Temer, unlike Rousseff, had been accused of taking millions in bribes.
In the final trial, Russeff's opposition needs a two-thirds majority, or 54 votes, in the Senate to impeach her.
In order to escape impeachment, Rousseff needs to change the minds of a handful of senators -- but it will be a highly difficult feat.
According to earlier reports, the impeachment trial is expected to take place in late August or early September.
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