Camilla will be making her first trip to Papua New Guinea, Australia and New Zealand, in a private or public capacity, when the royal couple's Jubilee tour begins on Saturday.
Charles, a seasoned traveller, has visited the southern hemisphere nations many times.
He represented the Queen at Papua New Guinea's independence ceremony on September 16, 1975.
In a message to the country's Prime Minister Peter O'Neill and the Governor General, Sir Michael Ogio, sent last month, he said:
"We are both greatly looking forward to experiencing the wonderful, culture and hospitality of Papua New Guinea, which I remember so well from my previous visits all those years ago."
The Prince of Wales and Duchess of Cornwall will be afforded a special welcome when they begin a tour of Papua New Guinea on Saturday.
The royal couple will arrive in the capital Port Moresby and be greeted by the Prime Minister, a 21-gun salute fired by the Papua New Guinea Defence Force, and a guard of honour.
The Prince of Wales and Duchess of Cornwall are to begin a Diamond Jubilee tour in honour of the Queen in Papua New Guinea, Australia and New Zealand in a two-week trip.
Charles and Camilla's celebration of her 60-year reign will include a traditional Aussie barbecue with outback sheep farmers and time with race goers at the Melbourne Cup.
They will also be given a sneak preview of the film The Hobbit: An Unexpected Journey by director Peter Jackson.