Police vehicles and rubbish bins were set ablaze as police and protestors clashed, leading to dozens of arrests and some injuries.
Some 10,000 demonstrators were estimated to be taking to the streets of Frankfurt according to the "Blockupy" group which is protesting against the ECB's austerity measures against Greece.
The protest was intended to be peaceful, yet police have used water cannon to clear a path through protesters blockading the entrance to the new ECB double-tower skyscraper which is due to stage its ceremonial opening today.
Protests began as early as 6am, and have led to "violent outbreaks at several locations in which police have been attacked" according to police spokeswoman Claudia Rogalski.
Ulrich Wilken, one of the organisers of the protest, told Reuters: "Our protest is against the ECB, as a member of the troika, that, despite the fact that it is not democratically elected, hinders the work of the Greek government."