The 62-year-old actor checked in to the Hazelden Addiction Treatment Center in Center City, Minn., earlier this week. He plans to stay for several weeks, and is partaking in a long-term sobriety program in a section of the facility called The Lodge.
"After working back-to-back projects, Robin is simply taking the opportunity to fine-tune and focus on his continued commitment, of which he remains extremely proud," the actor's rep said in a statement to TMZ.
Williams struggled with a cocaine addiction in the late 1970s and early 1980s, but managed to quit the drug and remain sober for 20 years. He checked in to an Oregon substance abuse clinic in 2006 after he started drinking again and admitted he was an alcoholic.
The busy actor is scheduled to appear in a number of upcoming films. He will star in Merry Friggin' Christmas and Night at the Museum: Secret of the Tomb later this year, and Mrs. Doubtfire 2 and Absolutely Anything in 2015.