Reading and mathematics standards in disadvantaged schools are on the rise - but still lag behind mainstream national schools, a study found.
The Educational Research Centre (ERC) evaluated the skills of thousands of youngsters in Deis primary schools in urban areas.
Dr Susan Weir, research fellow, said both reading and maths levels have improved significantly in schools over the last six years.
"The test data indicate that the reading and mathematics achievements of pupils in Deis schools are below that of national samples," she said.
"However, the data collected last spring show that average test scores have continued to improve at all grade levels in both reading and mathematics.
"In other words, the gains observed in 2010 had not only been maintained, they had been built upon.
"This means that the achievement gap between pupils in Deis schools and in national samples - particularly in the more junior grade levels such as 2nd and 3rd class - has narrowed significantly."
The report analysed test results from over 17,000 primary pupils in second, third, fifth, and sixth classes in 119 schools in the school s upport programme (SSP) .
Gains were particularly evident in the junior grades and in schools that had high levels of disadvantage, the ERC said.
It found second class pupils scored 26 out of 40 in reading 2013, up from 24.3 in 2010 and 22.8 in 2007.
"While this represents a significant increase, it should be noted that it is still below that of the norm group average for second class of 29 items correct," the report stated.
Elsewhere in maths, the percentage of pupils achieving very low test scores decreased over the six years - with pupils in second and third class not too far from the national average of 10%.
It also found the percentages of pupils absent for testing at each grade level fell from 10.8% in 2007 to 7.1% in 2013, while less than 1% of pupils were exempted from the tests by teachers because they had a learning disability or poor ability in English.
Education Minister Ruairi Quinn said the results are very encouraging.
"They show that the significant investment that we make in these schools is paying off and pupils' reading and mathematics test scores are consistently improving," he said.
"I'd like to pay tribute to the schools, teachers, parents and especially the children in these Deis primary schools who, despite the hardships that the economic downturn has brought, are continuing to improve in the building blocks of learning - reading and maths."
There are more than 850 Deis schools - 658 primary and 194 post-primary - with almost 166,000 pupils in the school support programme.
The aim of Deis is to ensure that the educational needs of children and young people from disadvantaged communities are prioritised and met.
The programme cost the education department 95 million euro in 2012, including 14m euro in Deis grants and 1,036 additional teachers - costing 63m euro.
Additional funding is also provided by the Department of Social Protection and the Department of Children and Youth Affairs for the school meals programme and the school completion programme.