80% of autistic people on incapacity benefit questioned wanted to work
A third of the 18,000 people with autism in Wales have no job and no benefits and are forced to rely on family and friends, says a charity.
The National Autistic Society Cymru said the majority wanted to work but lacked the help needed to find a job.
It said 80% of sufferers need help to apply for benefits and want it made easier for them to find work.
The Department of Work and Pensions said arrangements were in place to help those seeing advisers, if required.
The Don't Write Me Off report found there was a lack of understanding of autism amongst employment and benefits advisors and a shortfall in specialist employment services.
Half of people with autism have spent time with neither work nor benefits, with a third currently in that situation.
Many were unaware they had the right to an advocate at benefits meetings, and in the worst cases parents were actively blocked from helping.
David Penny, 27, from Dinas Powys, has Asperger syndrome, a form of autism.
Mr Penny has a university degree but has had difficulty finding employment and had "significant" problems obtaining suitable benefits.
He now claims incapacity benefit and disability living allowance after a long battle to receive them.
He said: "Getting into university and completing the course was not easy, but the support I received from the disability officer was exemplary, and poles apart from the support and understanding I had since then.
"Looking back at the application process and medical assessment for incapacity benefit in particular, I don't think they were ever meant for people with my kind of disability.
"The questions asked failed to capture any of the difficulties I have in life.
"I was never offered a meeting with a disability employment advisor, and relied on my mum for support.
"This had an effect on my behaviour, because I have difficulty dealing with stress.
"Because some people with Asperger syndrome can achieve academically, we may still need more support than our peers."
The Welsh Assembly Government published an autism spectrum disorder strategic action plan in 2008 and set up a task group to look at the needs of adults.
NAS Cymru wants the group to consider issues relating to employment before making final recommendations to the assembly government.
Shirley Parsley, the charity's national coordinator, said: "People with autism say their experiences of the employment and benefits system are marred by anxiety, confusion, delays and discrimination.
"It is absolutely vital they are able to access the right help and services if seeking employment and are supported financially when they cannot work.
"We are also calling on the Welsh Assembly Government to act in order to improve the chances that people with autism have in gaining employment."
In a statement, the Department for Work and Pensions (DWP) said: "We understand that people with autism have complex needs so we have arrangements in place to help, such as bringing along someone to represent them in adviser interviews if needed."
An assembly government spokesman said: "Wales is the only country in the UK to have a government-led strategy for autism. One of the key points of this plan is to look at training and employment opportunities for adults with autism.
"We are currently working with Job Centre Plus, Careers Wales and employers to develop awareness materials which focus on the positive impact of employing adults with autism and the benefits they can bring to a business."
The Welsh launch of Don't Write Me Off takes place on Wednesday evening.