Efron, who has starred in "High School Musical," its sequel and the movie musical "Hairspray," was hounded by questions about his girlfriend, Vanessa Hudgens, during a previous visit to Australia.
Naked pictures of Hudgens were leaked onto the Internet without the teen actress’ permission this summer.
Efron refused to comment on the scandal, but said he was looking forward to "chilling'' in Sydney this time around, The Daily Telegraph reported.
"I just want to have fun this time,'" he said.
"I'm not going to tell anyone what I'm doing, but it's going to be hanging out and there's going to be water close by. I always love going to Cafe Sydney for a giant seafood platter."
Efron is in town to co-host the Nickelodeon Kids' Choice Awards with The Veronicas singers Lisa and Jess Origliasso.