They said if their safety continues to be at risk, so will the regular delivery of mail.
There have been a growing number of violent attacks on mail carriers in the Chicago area.
"Today it is open season on the letter carriers and it is uncalled for, it is unnecessary and action needs to be taken immediately," said Luis Rivas, president of the Illinois State Association of Letter Carriers.
The ISALC and the National Association of Letter Carriers are both calling for federal and state prosecutors to "prioritize cases involving crimes against letter carriers."
"We demand that respect and we demand that protection and we demand it right now," said Brian Renfroe, president of the NALC.
Last week robbers targeted at least three postal workers in the city and suburbs. One letter carrier was shot in the leg and is still in recovery.
"I am echoing the fears of my members of having to come to work in fear, scared and wondering if they will be the next victim," said Elsie Foster, president of NALC Branch 11.
"Somebody needs to protect us on the streets. We deliver the mail!" said Mack Julion, assistant secretary-treasurer for NALC.
Renfroe said the labor union is also calling on elected officials to step up when it comes to enforcing postal workers' protection.
"We serve our communities and we have a right to be safe and to be protected when we are doing our job," he said.
Congressman Danny Davis, along with Chicago city and union leaders, all stand in solidarity with the postal unions and their workers, who said they just want to be able to support their families and come home safely.
"When they leave their families to go to work, they just want to come back safely at the end of their work day," Foster said. "We are the number one delivery."
The NALC said so far there have been more than 90 attacks involving letter carriers in the city over the past 12 months, including one vehicle break-in just this past weekend.