Tuesday is the 25th anniversary of the first May Day troubles in the city, when police used tear gas on rioters who burned out shops and turned over at least one police van. May 1 is traditionally a day for political marches - internationally it is a day for demonstrations of solidarity for workers, and has often been used by the far Right for counter marches.
Since 1987 Berlin riots have become an annual event, with many people coming into the city centre to fight the police. Over the last few years, Walpurgis night on April 30 has morphed into a "warm up" for May Day, with clashes between demonstrators, party-goers and police.
Police said that 3,000 officers would be on duty on the night of April 30, when hundreds are expected to take part in an "anti-capitalist Walpurgis Night" in the northern district of Wedding.
Some 15,000 demonstrators are expected on Tuesday evening, with up to 7,000 police officers on duty throughout the city. Police said their officers would show restraint, but that troublemakers would be targeted.
New protest routes have been planned to go past the German finance ministry and other major buildings.
Despite the talk of restraint, the police force is prepared to introduce potential May Day rioters to their new "little friend" – the state-of-the-art water cannon truck "WaWe 10".
The four-metre-high colossus is armed with three cannon on the front and sides, which shoot water to a distance of 60 metres. Anyone who gets in the way can expect serious bruises and even broken ribs.
It also has other settings, including the "water-wall", designed to simply soak people who get too near, without injuring them.
The WaWe 10, with its 10,000-litre water tank and €1-million price tag, has only been part of the Berlin police force since October 2011.
Berlin Mayor Klaus Wowereit has called for calm ahead of the traditionally tense day, while the city's interior minister Frank Henkel has expressed confidence in the police.
"The police have acquired a lot of experience of large-scale situations in the last few years," he told Die Welt newspaper. "I have complete trust in the experienced police commanders."
The far-right National Democratic Party (NPD) has also planned three demonstrations in the eastern part of the city on May 1, increasing the possibility of violence.