The 26-year-old, Arsenal's leading Barclays Premier League goalscorer, was taken off on a stretcher just 12 minutes into the game in Pescara after a challenge by defender Giorgio Chiellini.
He was later flown to Amsterdam's highly respected Academical Medical Centre, where he had a scan on Sunday night.
Agony: Robin van Persie lies injured clutching his ankle (above) and is treated by medics on the pitch during Holland's friendly draw with Italy (below)
'The prognosis is that I will be out for four to six weeks,' Van Persie told the Dutch television station NOS.
He was assessed in Amsterdam by Professor Cornelis Niek van Dijk, anorthopaedic surgeon who has operated on Cristiano Ronaldo, Ruud vanNistelrooy and Michael Owen.
A Dutch FA spokesman said: 'Robin van Ppersie has a partially ruptured ligament of his right ankle.
Rushed to hospital: Arsenal star Van Persie is taken away on a stretcher
'The Arsenal striker went to the hospital on Sunday evening, wherefurther examination confirmed the earlier diagnosis of the medicalstaff of the Netherlands team.'
Arsenal boss Arsene Wenger is already missing striker Nicklas Bendtner, who is recovering from groin surgery.
Van has scored eight goals in his last 11 matches for the northLondon club who are second to Chelsea in the Premier League.
Arsenalhost Carlo Ancelotti's league leaders at the Emirates on November 29.
Move over Cesc Fabregas: Aaron Ramsey is ready to step up and shine at ArsenalArsenal striker Van Persie insists: I'm not a 'killer' like Torres or DrogbaCompetition: Win tickets to see Arsenal v Standard LiegeARSENAL FC