Cameron has been sentenced to five years in jail for drug trafficking. He was arrested last year at the trendy Gansevoort Hotel in New York. He pleaded guilty to drugs charges in January.
Federal Judge Richard Berman ruled on the side of leniency, sending the 31-year-old to just five years behind bars rather than the minimum of 10 under federal sentencing guidelines.
Prosecutors said the judge didn't have to impose the minimum sentence, reports the New York Post.
With his actor father present in the crowded Manhattan courtroom, the judge said Douglas will serve only four years since he will get credit for the eight months he has spent in lockup since his arrest.
In court, Cameron apologized to his family and said that he was grateful for the chance to clean up his life.
'First, I'd like to apologize to my family... for my behavior... I'd like to ask you for the opportunity to be a productive family member and a good role model,' he said.
Cameron will also have to pay a US$ 25,000 fine, serve 450 hours of community service once he is released and undergo weekly counselling sessions with members of his family.
Image: A file picture of Michael Douglas and son Cameron | Photograph: Fred Prouser/Reuters