Lucio Barani was said to have gestured in the direction of Barbara Lezzi from the opposition Five Star Movement (M5S) on Friday.
Vincenzo D'Anna is thought to have repeated the gesture.
Female senators from various parties responded, demanding that Mr Barani apologise.
The Senate speaker suspended Friday's debate on Italy's constitutional reform bill in the subsequent pandemonium.
The two centre-right senators insisted their actions were misunderstood, but were nonetheless suspended by the speaker's council on Monday.
The speaker said the incidents were "so serious they offended persons and senators, and undermined the credibility of the institutions," news agency Ansa reported.
M5S Senator Alberto Airola was also suspended for a day for insulting members of government.
Two Italian senators have been suspended for five days after allegedly making obscene gestures at female colleagues during a senate debate.