It is the most competitive exam in the state and for more than 10,000 students, the results will probably be a disappointment.

On Thursday, a record number of year 6 students sat the annual entry test for one of 4226 spots in NSW's 21 selective and 26 partially selective schools.

This year an extra 1000 students sat the selective schools test across the state, with numbers rising from 13,442 last year to 14,458 this year.

Students from 964 public schools and 424 private schools did the exam at 154 test centres across NSW. But less than 30 per cent will get in.