"Peter steps into the booth with immediate effect," says chairman Mats Larsson to the club's website.
Andersson took Malmö to two semifinals during his previous time in Malmö.
He kicks off with a match already on Thursday night, away against Örebro.
Malmö is in twelfth place, one point away from relegation.
"In the situation we are in, it feels very good for us to get Peter into the staff.
He knows the club very well from before and has a relationship with very many in the team after his previous time with us ", says Mats Larsson.
Andersson says that he followed the team during the season and wants to help.
"It will be fun and I hope we can make something good out of this time.
Now it's straight into the hot air.
It is important that we play together and that everyone does the job and follows the structure ", says Peter Andersson.