Children with specific learning difficulties (SpLD), such as dyslexia, are three times more likely to fail their national curriculum tests, a survey by BBC One's Real Story has found.
Teachers said children with a specific learning difficulty were more likely to fail SATs
And 60% of teachers say children who fail their primary school Sats (Key Stage 2) will also fail their Sats in secondary school (Key Stage 3).
John Bangs, head of education at the National Union of Teachers, said the survey showed the need for a national professional development programme for teachers which would include greater emphasis on special needs.
The British Dyslexia Association (BDA) said the survey's results were startling but not surprising.
An Ofsted report last month said a quarter of all schools were failing to meet required standards.
Chief Inspector Christine Gilbert said that the gap between the best and worst schools was "unacceptable".
Recent primary Sats results showed no real improvement on last year with between 20% and 25% children still failing in maths and English.
In July the House of Commons education and skills select committee report into special education needs in schools said the entire SEN policy should be overhauled and it also said teacher training should be improved.
Education Secretary Alan Johnson responded to the report by promising that teaching support for these children and others with special needs would be "strengthened to ensure the right expertise in place in the classroom".
But the survey, commissioned specially by Real Story to coincide with the screening of Teacher Squad on BBC One, (Wednesday 13 December, 1900 GMT) also found that a third of teachers expected children with SpLD to under-achieve at school.
Specific learning difficulties include dyslexia, ADHD, dyspraxia and dyscalculia.
The findings also show that children with SpLD are three times more likely to fail Key Stage 2 Sats than other children.
Judie Stewart, chief executive of the BDA, said: "Many dyslexic children are failing in the school system.
"We know that these poor results are unnecessary.
"If children are assessed early enough in their school life and supported with multi sensory teaching then they will be receptive to lifelong learning and have a greater chance of success."
Multi sensory teaching requires educating children through audio, visual and interactive methods.
The BBC survey found that one in ten teachers use no multi sensory methods while a further quarter use these methods in less than 40% of their lessons.
Mr Bangs said extra trained staff were needed for classes with a high proportion of children with SpLD.
More than half of teachers agree that undetected or unmanaged SpLD will have a big or very big impact on the failure rate of children in school.
Real Story followed the work of charity Xp (Extraordinary People) in Walworth School in London.
The charity provided specialist trainers to work with teachers and pupils.
An unexpected 40% of the year 7 children were found to have dyslexia and of those children who were given extra tuition all improved their reading ages by between one and five years.
Children are not routinely screened for these learning difficulties either in primary or secondary schools but over half of those surveyed believe that there should be compulsory screening for SpLD in secondary schools.
Real Story is transmitted on BBC One at 1900 GMT on Wednesday 13 December 2006.