Group One-winning jockey James Winks has announced his retirement from the saddle on medical advice.

The 36-year-old revealed the news on Racing.com's After The Last program on Wednesday and said he had made the decision after being diagnosed with syncope, the medical term for fainting.

The diagnosis was confirmed when Winks underwent testing after suffering a medical episode at his Melbourne home.

Syncope is exacerbated by fasting and sweating and Winks said medical experts advised him he would have another episode if he returned to race riding.

"In laymans terms, syncope is caused by physical stress that my body undergoes daily and those physical triggers that contribute to the episodes include my sweating regime and the fact my body is dehydrated, which we all know is part and parcel of being a jockey," Winks told After The Last.

"Unfortunately, on medical advice it's in my best interests to force my early retirement.

"With that being said, the decision has been made for me to call time on my career in the saddle as a jockey and now I'm looking forward to the next chapter that lays ahead."

Winks has enjoyed a successful career winning four Group One races in Australia, including the 2008 Caulfield Stakes on Douro Valley and the 2010 Coolmore Stud Stakes on Star Witness.

His final ride was at Wodonga on July 19.

Winks said he would like to remain in the racing industry in some capacity.