AaB have terminated the contract with head coach Menno van Dam with immediate effect, says the club on its website.
The announcement came a few hours after AaB lost 2-3 at home to Sonderjyske on Sunday evening in a direct clash between two of the relegation candidates in the Danish Superliga.
The dismissal comes after a longer period of generally unsatisfactory results, explains the club's sports director, James Gow.
"Lack of results and an unsatisfactory development in terms of play are the main reasons why we unfortunately believe that parting ways with Menno van Dam is the right decision for AaB."
AaB have only one win and 11 points to show for the last 17 matches.
In the press release, Dutchman Menno van Dam makes no secret of the fact that he would have liked to have continued in the job.
"I am disappointed to have to leave AaB earlier than planned, but I respect the club's decision."
"I am proud of the way we have worked together with honesty, mutual respect and commitment from both the staff and the players", says Menno van Dam and wishes the club "success in the future".
After Sunday's defeat, AaB are in tenth place with 23 points, and the club is only four points from the relegation zone, where Lyngby and Vejle are at the bottom. The two clubs have played one game less than AaB.
AaB say that they expect to have a new head coach in place, when the club faces Vejle at home in a week's time.