Brown ignored questions from reporters as he entered the Los Angeles Criminal Courts building. The probation hearing stems from a 2009 assault on his then-girlfriend Rihanna.
But the hearing took on added significance after Brown's arrest last month at a Washington, D.C. hotel, where he is accused of assaulting a man who tried to get in a photo with him.
Los Angeles County prosecutors on Wednesday stopped short of asking for his probation to be revoked. Instead, Brown and his attorney, Mark Geragos, agreed to have Brown's probation modified.
The 24-year-old R & B singer will have to take part in a 90-day residential rehab program, complete 24 hours a week of community service, submit to periodic drug testing, and take medication prescribed by his doctor. Brown must remain in Los Angeles County unless it's so that he can attend legal proceedings in Washington.
Meanwhile, the courts will prepare a report on the incident in Washington, and it will be presented to a judge on Dec. 16. Brown denied hitting the man but was charged with misdemeanor assault.