Maggie Bowen, deputy chief executive of Autism Cymru, called for all mainstream teaching staff to receive basic training in special needs teaching after it was revealed that more pupils are being diagnosed with the condition.
Experts say children with an autistic spectrum disorder (ASD) benefit from a more structured approach to teaching. But pupils will be given a choice of activities under the new FP curriculum, starting this September for under-fives. One scenario would be a class choosing between a myriad of play items, including sand or water.
There is currently no official training on ASDs for new teachers in Wales. However, experts see it as the key to making inclusion work, and to improving bad behaviour in the classroom. Earlier intervention in diagnosing an ASD could also improve many children's life chances.
But although she is advocating structure, Ms Bowen also believes pupils need to be listened to more and given other choices.
Almost 1,000 pupils with an ASD are taught in Welsh schools. Ms Bowen said some of them have significant academic strengths - often in ICT or scientific subjects - and could be allowed to set their own goals and choose rewards.
Enid Moore, manager of the autism communications centre at Darland High School in Wrexham, said that teachers in mainstream schools must be flexible about children with the condition. She said some children on the autistic spectrum cannot speak, while those with Asperger's syndrome might do well academically but find it hard to relate to others socially, requiring big contrasts in teaching techniques.
During story time, for example, a child may not want to sit on the carpet or make eye contact with the teacher.