The roughly three-and-a-half hour show, broadcast on CBS, averaged 25.3 million viewers, according to Nielsen ratings. It was the show's lowest turnout since the 2009 telecast, which drew just 19 million viewers.
Viewership was down about 11% from the 28.5 million people who tuned in to last year's show. In the key 18-to-49-year-old demographic, this year's show dropped about 14% from last year to a rating of 8.5.
Unlike the Emmy Awards, the Golden Globes and Academy Awards, the Grammys are not broadcast live across the country.
CBS has historically chosen to air the music show on a tape delay on the West Coast with the idea that more viewers can watch the show between 8 p.m. and 11 p.m.
But social media backlash from West Coast Twitter users suggests some are still unhappy about the time delay.