The man was driving on Boys Lane in the city when his car was involved in a collision just after 8pm last night.
Firefighters said there were no other injuries apart from the man who got his foot caught.
Crew manager Wane Ward said: "The chap's foot became trapped in his car's foot pedal and we had to ease it out.
"He had to go to hospital with a suspected broken ankle."
Two fire engines from Fulwood and Preston were called to the incident.