It was Tarantino's best opening ever, exceeding the $25.1 million haul for 2004's "Kill Bill - Vol. 2." Overseas, "Inglourious Basterds" added $27.5 million in 22 countries, giving it a worldwide total of $65.1 million.
Released domestically by the Weinstein Co. and overseas by Universal, "Inglourious Basterds" features Pitt and an international ensemble in a sprawling tale of Jewish commandos and a plot to take out Nazi leaders at a movie premiere during World War II.
The film provided a much-needed hit for Harvey and Bob Weinstein, who have managed only lackluster receipts at their new outfit since departing Disney-owned Miramax four years ago.
At Miramax, the Weinsteins balanced prestige and profit with a string of Academy Awards triumphs such as "Shakespeare in Love" and "Chicago" and hits such as Tarantino's "Pulp Fiction" and the "Scary Movie" and "Scream" franchises.
"Tarantino helped build the house of Miramax. He's proving right now that he's helping to build the house of Weinstein," said Paul Dergarabedian, box-office analyst for Hollywood.com.
So far, the Weinstein Co. has been unable to reproduce that Miramax success, its lineup burdened by box-office underachievers such as last year's "Soul Men" and 2007's "Grindhouse," Tarantino and Robert Rodriguez's B-movie double-feature.
Harvey Weinstein said critics continually write off him and his brother, including a magazine piece in 2002 "saying we were the flavor of the '90s but we were kind of over in the new millennium."
Weeks later, he noted, Miramax scored 40 Oscar nominations, among them three of the five best-picture nominees, including eventual winner "Chicago."
Weinstein said his new company has a strong lineup ahead, including next weekend's horror sequel "Halloween II" along with "Chicago" director Rob Marshall's musical "Nine" and the post-apocalypse saga "The Road" late in the year.
Rodriguez, Tarantino's "Grindhouse" partner, did not fare so well with "Shorts," his Warner Bros. family comedy that debuted at No. 6 with just $6.6 million. The movie features William H. Macy, James Spader, Leslie Mann and a cast of kids in a series of loosely linked adventures centered on a magic rock that grants wishes.
Fox Atomic's comedy "Post Grad," with Alexis Bledel as a college graduate who moves back home with her eccentric family after she's unable to land her dream job, tanked with $2.8 million, coming in at No. 10.
The previous weekend's top movie, Sony's sci-fi thriller "District 9," slipped to second-place with $18.9 million. With a domestic total of $73.5 million, the movie is on its way to becoming a $100 million sleeper hit.
Hollywood's revenues were up for the third-straight weekend, a late-season surge that has helped the industry recover from a monthlong slide in receipts. Overall ticket sales were $134 million, up 27 percent compared to the same weekend last year.
The weekend put Hollywood back on track to break last summer's revenue record of $4.2 billion, though receipts this season are up only a fraction.
Factoring in higher ticket prices this year, movie attendance is running 3 percent below last summer's, according to Hollywood.com.
Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Hollywood.com. Final figures will be released Monday.
1. "Inglourious Basterds," $37.6 million.
2. "District 9," $18.9 million.
3. "G.I. Joe: The Rise of Cobra," $12.5 million.
4. "The Time Traveler's Wife," $10 million.
5. "Julie & Julia," $9 million.
6. "Shorts," $6.6 million.
7. "G-Force," $4.2 million.
8. "Harry Potter and the Half-Blood Prince," $3.5 million.
9. "The Ugly Truth," $2.9 million.
10. "Post Grad," $2.8 million.