Continuity mistake: Just before Secretariat's first race, the main characters are discussing tactics in the parade ring. In the background is a jockey in pink and gold colours standing by his horse. When the shot changes angles he is mounted and being led out onto the race track. This means that he would have only taken one second to mount and travel a distance of about 10 meters. A couple of shots later he suddenly appears again, but this time he is being led into the saddling-up area, even though the jockey is already on board.
Continuity mistake: While in the stable, Penny Chenery asks Miss Ham to step outside so she can talk to trainer Earl Jensen privately. Miss Ham exits out the stable door, the inside shot shows nothing but a row of windows to the left of the stable doorway. When Miss Ham hides just outside the same stable doorway to eavesdrop, there are no windows, and only equipment and hay hanging from the doorway. (00:11:30)