The first 24-hour walk-out will start at 6am on Friday (14 December 2012) when workers will strike in a dispute over pay and conditions.
Unite, which balloted its members at the Bevan Way and Dial Lane sites in Smethwick, West Bromwich and the Lincoln Street plant in Wolverhampton, said there were reports of a culture of "alleged bullying and beatings" at the company.
The workers voted by 98.5 per cent for strike action and 97.2 per cent for industrial action short of a strike. The turn-out was 57 per cent.
The next strike will be held on 18 December and the third is scheduled for 21 December.
Unite regional officer Des Quinn said: "The workers at 2 Sisters have voted overwhelmingly to take a stand against a paltry pay offer.
"The near unanimous vote in favour of strike action is the strongest possible message to management that they need to sit down and negotiate in good faith."
A spokesperson for 2 Sisters Food Group said last week when the threat of a strike emerged: "We are very disappointed with the reaction of Unite, as we have only had very initial discussions on how we can work together to remain competitive in a tough economic climate.
"The food industry remains challenging, as evidenced by recent events elsewhere in the industry. We will continue to consult on our proposals with unions and employee representatives, working together to ensure our sites can remain competitive for the future."
The spokesman also added it had not been approached by Unite about the "alleged bullying and beatings".
"We have not been made aware of any specific evidence of this by Unite and will be pressing them to do this, but we take any comment of this nature extremely seriously.
"We have proper channels for such allegations, including an employee whistleblowing helpline, and would encourage Unite members and employees to come forward if they have any evidence of this."