Three Perth children caught measles this week after they had contact with an non-vaccinated child in Rockingham.

The WA Department of Health released the information in its weekly virus watch report.

A case of measles. Credit:US Centres for Disease Control and Prevention

The three children, two of whom are babies, were exposed to the virus at Rockingham Hospital where the child of a non-vaccinating family was being treated for measles, reported The Weekend Courier.

It's understood the non-vaccinated child caught the virus in Bali.