That's up from 33 theaters on Friday.
By the end of Friday, Disney and Marvel Studios' Black Panther had already become the highest-grossing title in history at 33 AMC theaters across the country, according to the mega-exhibitor.
Put another way, Black Panther earned more at those cinemas on Thursday evening and Friday — along with advance ticket sales for other times during the weekend — than any other movie has in an entire weekend.
By the end of Saturday, the number of theaters setting revenue records climbed to 80 locations, more than 10 percent of the entire circuit.
AMC didn't provide a list of the theaters, nor a precise dollar amount for those cinemas, but noted that there were a record 83 showings on Friday at the AMC Southlake 24 near Atlanta.
"Black Panther has taken on a life of its own," AMC executive vp global programming and chief content officer Elizabeth Frank said.
Owned by China's Dalian Wanda Group, AMC is the largest movie chain in the world, including in North America, where it operates 661 locations.
Black Panther is shattering records in its box-office debut, grossing $192 million for the three-day weekend and a projected $218 million for the four-day Presidents Day weekend.
The film boasts one of the top openings of all time in North America and the second-biggest launch for a superhero pic, behind only fellow Marvel title The Avengers, which earned $207.4 million in its first three days, not accounting for inflation.
Directed by Ryan Coogler, the $200 million movie stars Chadwick Boseman as T'Challa/Black Panther alongside Lupita Nyong'o, Michael B. Jordan, Daniel Kaluuya, Letitia Wright, Winston Duke, Angela Bassett, Forest Whitaker and Andy Serkis.
The story follows T'Challa as he is sworn in as king of Wakanda, a cloaked, technologically advanced nation in Africa that's home to the exotic metal vibranium, which powers much of Black Panther's tech.
Feb. 18, 8:15 a.m. Updated with revised theater count.