They held up signs that read, "Quitness" and "Play Like It's Game Five" - a reference to his playoff failure against Boston last season, when many fans - and owner Dan Gilbert - felt James had quit. There were five guys wearing a single letter each on their white T-shirts that spelled out: LeBum.
It was James' first game back in the city where he played for seven years and won back-to-back MVP awards, but failed to win an NBA championship.
But the noise and the signs didn't seem to phase the former Cavalier. He scored 10 more points than Cleveland's entire starting lineup.
James scored 38 points - 24 in a virtuoso third-quarter performance - to lead the Miami Heat to a 118-90 win on Thursday night, turning his hostile homecoming into another embarrassing moment for the Cavaliers.
Despite the bad feelings he created with his abrupt departure from Ohio, James says those fans shouldn't expect any apologies.
"Decisions I make, I live with them. There's always ways you can correct them or ways you can do them better, but at the end of the day, I live with them. I'm satisfied, i'm happy right now," he said.
James also said that knowing the Cleveland court as well as he does definitely helped him on Thursday night.
The Associated Press Contributed to this report.