In a photograph from the ceremony, the British singer - who won an award for 'Best Pop Solo Performance' - appears to be confronting Brown during the event.
It is not clear what the pair were discussing, although a widely circulated clip on the internet shows that Adele was apparently unimpressed with Brown during the ceremony.
When Frank Ocean picked up a gong, he received a standing ovation. However, Brown remained seated, receiving a glance from a nearby Adele.
Ocean and Brown have a difficult relationship following their recent brawl outside a recording studio, in which Brown or a member of his entourage reportedly described Ocean with a homophobic slur. However, Ocean has decided not to press charges.
Meanwhile, Brown attended the Grammy Awards with Rihanna - four years after the pair missed the ceremony because Brown had physically assaulted the 'Umbrella' singer.
Grammy Awards 2013 winners - Photo gallery:
Copyright: PA Images Matt Sayles/AP