Trainer Grahame Begg is to shut his Randwick stable, ending a family association with the famous Sydney racetrack spanning almost half a century.

Begg, who has won 12 Australian Group One races, will wind up the stable's racing commitments next month.

"After 25 years I am closing my Randwick stable in December," Begg posted on Twitter.

"Thank you to my family, clients & loyal staff."

Begg learned about racehorses while working under his father Neville, who after opening stables at Randwick in 1967, went on to become one of Sydney's best trainers.

As his father's right-hand man, Begg was associated with many top-class gallopers.

But none were better than Emancipation, one of the finest racemares of the modern era.

When his father was lured to Hong Kong to train in 1990, Begg took over the Randwick operation known as Baramul Lodge and enjoyed instant success.

Barely a few months after he was granted a trainer's licence, veteran galloper Eye Of The Eye saluted for him in the 1990 Doomben Cup.

It was not long after that Begg trained Whisked to win the Thousand Guineas during the Victorian spring carnival.

Whisked earned further fame away from the racetrack as the mother of champion stayer Tie The Knot.

Eye Of The Sky and Whisked would be the first two of seven Group One wins during the 1990s while Begg made an impact on the global stage when Monopolize won back-to-back Hong Kong International Bowls.

The most recent of Begg's Group One triumphs came at Randwick in 2011 when Secret Admirer claimed the Epsom Handicap.

He also trained Ilovethiscity to win the Randwick Guineas in the same year.

Begg has one acceptor at Randwick on Saturday, the last-start Warwick Farm winner Wine `n' Dine who is rated a $26 chance in the Choose Segenhoe Handicap.

"It is a way of life," Begg once said of the seven-day-a-week demand of training a string of racehorses."