Boks lose Venter's expertise
Venter, one of the masterminds behind the Azzurri's historic win over the Springboks in November, recently suggested he might be available to assist Bok coach Allister Coetzee.
However, with the South African Rugby Union having been dragged its feet in making a call on Coetzee's future, Venter accepted an offer from the Italian federation (FIR).
Venter, who was also the mastermind behind the rugby indaba in October, has signed on as a defence coach with the Azzurri.
The FIR made the announcement of Venter's appointment in a media release on Monday.
"I played and worked with Brendan at London Irish in the past," Azzurri head coach Conor O'Shea said.
"I believe that this agreement is the best it can be, for us and for him.
"Brendan has had a great impact on the group [in November]," he said of the win over the Boks.
"We are excited to be working with him for years to come.
"He's a coach that is respected by the whole international community and we are proud that he wants to join our project with Italy until the next World Cup."
Italy, who finished last in the 2016 Six Nations, start their 2017 campaign when they host Wales on February 5.
Venter, a member of the World Cup-winning Springbok team in 1995, had previous coaching stints with the London Irish, Saracens and the Sharks.
His departure came just days after Rassie Erasmus' lawyer, Frikkie Erasmus, told rugby365 that the Munster-based former Bok loose forward will not be coming to SA to talk to SARU about his possible involvement with the Boks.