Zarate was one of Lazio's shining lights last season as the capital city club claimed Europa League qualification by finishing fifth in Serie A.
However, the Argentinean was linked with a move away from Lazio all summer long, with reports suggesting he was looking for a new challenge.
And Zarate got his wish on Wednesday when Inter sealed his services on a loan deal which could yet be made permanent.
Zarate has recently been hit by suggestions that he is slightly overweight and not in prime condition for the start of the new Serie A season, but speaking at his unveiling as an Inter player on Friday, Zarate was keen on setting the record straight.
"When I was in Argentina with my friends on holiday, I ate a lot of food and so I came back a little overweight, but I have lost this in pre-season and so I am ready to play," Zarate said.
Zarate was brought to Inter along with Uruguayan international Diego Forlan to bolster the Nerazzurri's attacking options following the sale of Samuel Eto'o to Anzhi Makachkala.
And while Zarate concedes Eto'o did well for Inter, he believes Forlan and himself can bring something different to the Inter attack.
"Eto'o is a great player, but this is a new season and both myself and Forlan are different players."
Another new Inter signing, Andrea Poli, was also unveiled on Friday, who like Zarate, joins Inter on a season-long loan deal from Sampdoria.
Poli was quick to reveal his pride at joining the Nerazzurri, and was eager to contribute as soon as possible.
"I am very proud to join Inter and I cannot wait to start.
"This is a great club with great champions and I want to do well for the team and the coach."
Following a delay to the Italian football season due to strikes, the new Serie A campaign looks set to start next weekend, where Inter will travel to take on Palermo, whom they beat in last season's Coppa Italia final.