The 21-year-old singer spent much of April recovering from what was described as a "severe allergic reaction" to antibiotics, forcing her to postpone a series of U.S. tour dates.
She was released from the hospital at the end of April, but postponed more tour dates when her symptoms returned.
Cyrus, who tweeted "so f***ing xxxited to get back on touuuuuuuurrrrrr," got back to work on Tuesday.
She made her usual entrance, sliding down a giant replica of her own tongue.
The singer also urged attendees to kiss each other, sang a cover of Dolly Parton's "Jolene," and humped the top of a car wearing a unitard made of fake money.
Swim Week Miami Beach 2014 [PHOTOS]