Brian Meldrum revealed on Monday (December 19) that he is optimistic about his seriously ill sibling's progress.
"I am totally optimistic he will pull through this and the future will look after itself then," the Herald Sun quotes Brian as saying.
He later told ABC Radio that Molly's recovery was "going to plan", but that it was still "a waiting game" for staff treating him at Melbourne's Albert Hospital.
Molly - born Ian Meldrum - fell from a ladder at his house last Thursday (December 15) while hanging Christmas decorations and suffered multiple injuries including a skull fracture.
He is currently in an induced coma so that bruising to his brain can subside.
Molly has interviewed international stars including Beyoncé, Kylie Minogue and Susan Boyle during a career which has spanned almost five decades.
Australian prime minister Julia Gillard is among those who have penned get well messages for the music mogul on Twitter.
> Molly Meldrum furious with Twitter "imposter"