The battle has centred around a pay review which the unions claim would lead to some people losing as much as £18,000 a year.
But the council has counter-claimed that nearly half their staff would get significant pay increases.
The dispute has become increasingly entrenched with Birmingham officials claiming just 10% of staff – 4,462 people - had voted to go on strike.
The first stage of the strike is set to begin on February 5.
Unison regional secretary, Valerie Broom, said: ‘The result of today's ballot shows just how angry and frustrated UNISON members in Birmingham are.
‘Taking strike action is always the last resort, but the decision to impose grossly unfair new contracts has come as a hammer blow to staff and their families.’
The council’s leadership urged the unions to continue with negotiations.
Councillor Alan Rudge said: ‘We sincerely hope that we do not reach a point where council workers are going out on strike and damaging the services we provide for the people of Birmingham and would urge the unions to represent their members fully and to keep talking to us.’