The survey, which is being carried out in the Dublin, Wicklow and Kildare region, shows an autism rate close to 15 out of every 10,000 children. Six years ago, the survey showed a rate of five cases for 10,000 children.
Autism is a developmental disorder which usually becomes apparent before the age of three.
It mostly effects language, communication and behaviour al skills. Mr Pat Matthews, ISA executive director, stressed these were just preliminary results but said it was worrying. It's a very significant increase, for whatever reason. There may be a lot of factors playing a role, such as better diagnosis services and greater awareness of autism. But these factors still do not fully explain the increase.