The number of moviegoers reached 12.5 million in October, down 990,000 from the same month last year, according to the data compiled by the Korean Film Council (KOFIC) that tracks box-office sales.
Movie theaters' combined revenue also decreased by 4.2 billion won to 95.4 billion won during the cited period.
"My Love My Bride," a remake of the popular South Korean movie of the same title (1990) topped the local box office in October, attracting 1.95 million viewers, the data said.