Welsh Education Minister Jane Davidson has pledged to abolish compulsory school testing for 11 and 14-year-olds.
A report recommended tests be replaced by teacher assessments
She told assembly members on Tuesday that the tests would be phased out over the next four years.
Ms Davidson was giving her response to the Daugherty report, which recommended that the compulsory key stage tests should be dropped.
Most teaching unions have welcomed the proposals, but some fear it could mean higher workloads for teachers.
Key stage 1 tests for 11 year olds will be optional next year and then phased out altogether.
For Key stage 3 pupils aged 14, the test will remain for 2005, but then become optional. In 2007 the tests will be replaced by teacher assessment.
A new skills-based test for 10-year-olds based on skills will be introduced.
Key stage tests for younger children in primary schools were scrapped in 2002.
In May, a committee led by Professor Richard Daugherty recommended ending the tests for 11 and 14-year-olds as well.
His report, which was commissioned by the assembly government, recommended replacing the Key Stage 2 tests with skills tests in numeracy, literacy and problem-solving when children are 10 and teacher assessment when they are 11.
Jane Davidson abolished tests for seven-year-olds three years ago
It said testing at 14 should be replaced with further teacher assessment before children choose their options for GCSEs.
But the Westminster government has remained firmly in favour of the tests, commonly known as Sats.
England's School Standards Minister, David Miliband, said it was important to have independent, objective, national benchmarks of success at age 11.
Studies showed that children who did well at 11 would do well in their GCSEs at 16.
NUT Cymru welcomed the report saying National Curriculum tests "did not help teaching and learning" and that "they have become the ends instead of the means".
But another union, the NASUWT, said they feared scrapping the tests at 11 and 14 would lead to higher workloads for teachers.
Ms Davidson announced the abolition of the key stage tests for children younger than 11 in September 2001, saying they would concentrate instead on teacher assessment and play.