Purple Wiggle Jeff Fatt has undergone emergency surgery in a Sydney hospital following the diagnosis of a heart condition.
The 57-year-old is suffering from arrhythmia, a condition where the heart beats irregularly, and had been feeling unwell for several weeks, reports say.
Fatt was fitted with a pacemaker during the surgery on Friday.
He is expected to make a full recovery.
However, the surgery has forced Fatt to pull out of the group's upcoming US tour.
Fatt was one of the original members of the children's entertainment group when it was formed in 1991.
The Wiggles music group has grown to become a global phenomenon, having sold more than 23 million DVDs and seven million CDs worldwide.