The British Horseracing Authority says meetings will not be open to the public due to the coronavirus outbreak.
Racing organisers say meetings will go ahead as planned but some will be forced to cancel.
The ban will be in place until at least the end of March to try and stop the disease from spreading unnecessarily.
It comes shortly after the busiest week of the year for many in horse racing with the Cheltenham Festival taking place as usual.
The decision to push on as normal drew plenty of criticism with more than 250,000 in attendance over the four days in Gloucestershire.
Now, it has been decided that horse racing should not be open to the public until at least the end of March, though it is expected that may have to be revised if the virus continues to spread at its current rate.
Nick Rust, chief executive of the BHA, said: “The restrictions we are putting in place to close racing to spectators and limit attendees will reduce demand on public services.
“We also have a range of measures in place designed in response to the government's guidance on public health and we will continue to update these as appropriate.
“We are following the government's advice to strike a balance between protecting public health and maintaining business activity and will continue to do so. We thank our customers and staff for their support.”
