Jockeys Brad Rawiller and Brian Higgins have been taken to Melbourne's Alfred Hospital after a fall at Cranbourne.
A Victorian Jockeys' Association statement said the two were conscious and transported to hospital for further assessment and observation.
Rawiller was suffering concussion and chest pain while Higgins was sitting up but there were concerns with his ribs, lung and abdominal pain.
Racing Victoria stewards made the call to postpone the rest of Sunday's meeting following the fall in the fourth race after speaking with other jockeys.
"With our consultation with the riders and their concern for the welfare of their colleagues, the decision has been made to postpone the remainder of the meeting," RV steward James Hitchcock told broadcaster racing.com.
The fall comes a day after after visiting West Australian jockey Willie White suffered four fractured ribs and a fractured sternum in a fall at Avoca.