The offensive line coach will fill in for interim head Coach Joe Vitt, who will serve a six-game suspension in connection for his role the Saints' bounty scandal.
Vitt had been tabbed to replace head Coach Sean Payton, who is serving a yearlong suspension as part of the discipline handed out by the NFL in the wake of the alleged pay-to-injure scheme.
As part of the move, Kromer was promoted to linebackers/assistant head coach.
"He is very familiar with our team and with the methods we have been successful with," Saints General Manager Mickey Loomis said. "Ultimately, I wanted to have the least amount of change with both the offensive and defensive staffs, and maintain the most continuity with the program that has been in place for the last six years."
Kromer is in his fifth year with the team.