Racing NSW's longest serving chairman John Messara has announced he will retire from the position at the end of the year.

Messara said on Monday he had achieved what he set out to do in his five years at the helm of the state's racing industry.

Racing Minister Troy Grant said deputy chairman Russell Balding would assume the top position on Messara's retirement in December.

"It's been a privilege to serve the racing industry in such an outstanding team including the Board and the executive of Racing NSW," Messara said.

"All of our original objectives have been achieved during the five years.

"I wish to give special thanks to the chief executive, Mr Peter V'landys AM who has been a tower of strength during what has been an often challenging scenario."

Balding said NSW racing had thrived under Messara's leadership.

"John Messara is the longest serving chairman of Racing NSW and is an icon in the Australian Thoroughbred Racing Industry; he will be greatly missed," he said.

"Under his leadership the NSW Thoroughbred Racing Industry has regained its mantle as the leading jurisdiction in the southern hemisphere. Annual prize money has all but doubled from $118 million to $203 million during his term with particular focus on Country and Provincial racing.

"Importantly, NSW now has a flagship carnival in The Championships.

"In addition to driving substantial commercial growth and financial sustainability in the NSW racing industry, John also deserves recognition for the measures introduced to secure the integrity of the sport, including the establishment of the Investigation and Surveillance Unit, the establishment of a world class forensic laboratory and the licensing of veterinarians, just to name a few of his initiatives."

A statement from the minister said Balding would work closely with Messara in the coming months to ensure a smooth transition.

Grant said Messara had been a driving force behind some of the biggest improvements to thoroughbred racing in NSW.

"Thoroughbred racing has a bright future in this state and Mr Messara's advocacy for reform has played a crucial part in this - from stronger integrity measures for the sport, to wagering tax parity with Victoria.''

"Under Mr Messara's leadership, NSW finally has a premier racing event, the Sydney Autumn Carnival, which is expected to continue to grow from its strong foundation.''

Grant said the two casual vacancies on the board created by the retirement of Messara and the resignation of Jennifer Owen would be filled in accordance with the Racing Act.