The film has earned $24.2 million domestically since it debuted June 29 in theaters.

It takes over the No. 3 spot from "An Inconvenient Truth" behind Moore's "Fahrenheit 9/11" and the wildlife documentary "March of the Penguins."

"It's an incredible achievement for 'Sicko' to have become the third highest-grossing film in the history of documentaries," Harvey Weinstein said in a statement. "We are going to keep the movie in theaters and plan to re-release it during the fall, so that audiences continue to have a chance to experience this entertaining and profound documentary."

"Sicko" has been playing in theaters nationwide for more than nine weeks. It had the second highest-opening weekend of all time for a documentary.