Tower Bridge was closed to traffic during Monday morning's rush hour after a cyclist was hit by a car.
Police on patrol discovered the scene of a road traffic collision on Tower Bridge at 3.45am on Monday morning.
A 25-year-old male cyclist had been in collision with a Mini and was taken by London Ambulance Service to an east London hospital for treatment.
Police say that although his condition is serious, his injuries are not thought to be life threatening.
No-one has been arrested and Tower Hamlets Police are investigating.
Motorists were advised to avoid the area on Monday morning.