The 27-year-old singer is suffering from bronchitis and was told by an on-site medic to pull out or risk permanently damaging her vocal cords, TMZ reports.
Rihanna arrived to the Staples Center in Los Angeles for rehearsals earlier on Feb. 15, 2016, but did not walk the red carpet.
After rehearsing her song "Kiss Me Better" twice, she reluctantly decided to go with her doctor's advice and not perform, according to the website.
She then left the venue and went home to rest-up.
A rep for Rihanna told TMZ that the singer took antibiotics for three days but didn't improve and that on on-site doctor put her on 48 hours of vocal rest.
It's been a busy few days for the singer. On Feb. 14 Rihanna attended the MusiCares Person of the Year event honoring Lionel Richie in Los Angeles.
And on Feb. 13 the singer was in New York for the launch of her Fenty Puma Fall 2016 collection.
This is not the first time the singer has been forced to pull out of a Grammys performance.
Back in 2009 the Barbadian beauty canceled her performance at the show after she was assaulted by her then-boyfriend Chris Brown on the eve of the ceremony.