The mother of an autistic boy said she was "ashamed of society" after her eight-year-old son was asked to leave a performance of Shrek the Musical.
James Geater, from Worthing, West Sussex, was taken to the Theatre Royal Drury Lane in London with another autistic boy by four carers.
They were asked to leave the auditorium because they were too noisy. James's mother Karen said it was unacceptable.
The theatre said the party was asked to sit outside until James calmed down.
The trip was arranged for James, who attends a special needs school, by West Sussex County Council (WSCC).
Ms Geater, who has three other children, said carers had phoned the theatre before the visit to explain the boys' disabilities.
The party booked two boxes for the performance but did not stay until the end.
"I was told the boys were just excited and happy and were clapping and making some noises," she said.
"The staff kept barging in and telling them to be quiet, which in itself upsets autistic people.
"James is part of society and we have got to say we are not going to be treated like this.
"My son and lots of other children and adults are losing out and why should they if, through no fault of their own, they have a mental disability?"
WSCC said its aim was to enable autistic children to enjoy activities like any other.
"We naturally carry out assessments beforehand designed to address all possible risks," said a spokesman.
"We have been in touch with the theatre which has been helpful and advised us on the process for obtaining a refund, which we will follow."
The Theatre Royal Drury Lane is owned by the Really Useful Group.
"Staff asked the carers during the interval if they would sit outside during the second act until the little boy calmed down," it said in a statement.
"We are used to dealing with people with all sorts of disabilities and very often provide a quiet room.
"The carers took the decision to leave because the little boy could not be comforted."