The workers are seeking $15 an hour, more than double the current minimum wage in New York, which they say will bring them up to livable standards.
The workers also want more hours and the right to form a union without retaliation.
A number of fast-food chains are affected by the walkout, including Burger King, McDonald's, Domino's, Wendy's, and Papa John's Pizza.
The workers are asking customers not to patronize the fast-food restaurants until the changes are made.
The National Labor Relations Board has heard the complaints.
The strikes are being held in New York City, Chicago, St. Louis, Detroit, Milwaukee, Kansas City and Flint, Michigan.
Customers at fast food restaurants in Manhattan seemed to feel the workers deserve more money.
"They're often not getting the hours they need, and if that's the case, they're serving food and should be paid a fair wage," said Dylan Easterland.
"Anybody making under 15 dollars is not making enough money. You can't survive on minimum wage. You're paying money just to come to work," said Karen Henrique.
But one Wendy's customer said a good result for workers could be bad for customers.
"If they increase their wages, their product quality is not going to get any better. Only prices are going to increase," said James Busse.