The racetrack career of All Too Hard is over with the half brother to Black Caviar officially retired on Sunday.

Vinery Stud has shelved plans to race the colt at Royal Ascot and he goes out a last-start winner of the Group One All Aged Stakes at Randwick.

The latest international rankings rated All Too Hard Australia's second best racehorse behind Black Caviar who bowed as the highest ranked horse in the world.

"It was a difficult decision for us to retire a colt with so much more to offer as a racehorse," Vinery's general manager Peter Orton said.

"All Too Hard has done all we could have asked for and more.

"He possesses an outstanding pedigree being out of Helsinge and a half brother to world champion sprinter Black Caviar but offers the blood of champion sires such as Danehill, Snippets, Last Tycoon, Flying Spur and Vain."

Vinery bought All Too Hard late last year and he has won three consecutive Group One weight-for-age races for his new owners - the CF Orr Stakes, the Futurity Stakes and the All Aged Stakes - all over 1400m.

A win at Royal Ascot would have cemented a dual hemisphere stud deal.

The senior member of the Hawkes family training partnership, John Hawkes, said he was proud to have been associated with All Too Hard.

"We are obviously very disappointed to see All Too Hard retire, but we understand the owners' decision to do so," he said.

"You don't see too many colts as good as this horse come along. He is a super horse, he has shown just what he is capable of doing and would have potentially gone on to win many more top class races and in doing so establishing himself as one of the greats.

"We are proud to have been part of the colt's career on the track... and we look forward to training his stock in the future."