Aurora Cerullo, 14, had written a message online saying 'There is no tomorrow' after bullies told her to 'kill yourself' and called her a 'dog'.
Police are now investigating after the teenager was found lying next to her family's apartment building in Venaria, near Turin, on Monday morning.
Aurora is the third Italian teenager in a year suspected of killing herself after being trolled on the notorious website, which allows users to ask anonymous questions.
The apparent suicide follows the death last year of British school girl Hannah Smith, whose family say she was targeted by 'trolls' on the Ask.fm website, as well as two other deaths in Croatia and Ireland linked to the site.
In the weeks leading up to the tragedy, Aurora had been tormented by abusive messages on the question and answer site.
One cruel comment said: "Kill yourself. You're a dog."
Another said: "You are so ugly. How old are you- you look about 10."
Two days before she died Aurora was asked by one user of the site what her state of mind was. She posted an horrific picture of a young girl self-harming.
Above was the caption: "Are you OK?- yes."
The prosecutor for juveniles in Turin has already ordered the seizure of her computer and mobile phone.
Her elder sister told Italian newspaper Corriere della Sera: "We don't know why she did it. She felt ugly and said she would never get a boyfriend."
After the death of Hannah Smith ask.fm introduced a "bullying/harassment" button and promised to investigate any reports of abusive behaviour within 24 hours. But critics say the improvements do not go far enough and want to ban all anonymous posts.
A full inquest into the death of Hannah, from Lutterworth, Leicestershire, is to be held next month.