Dykstra admitted in municipal court Tuesday to violating city housing codes in Linden by running a rooming house without permission.
The former Philadelphia Phillies player pleaded on behalf of his company, Titan Equity Group.
As part of the plea deal, Dykstra will pay about $3,000 in fines.
The case is the latest in a series of legal issues for Dykstra, who has served prison time on charges including bankruptcy fraud and money laundering.
Dykstra said "I've got bigger fish to fry," while leaving the courtroom.
Linden officials and residents previously complained that Dykstra was destroying the quality of life in the area, turning the Stockton Circle neighborhood into a den of drugs and prostitution.