A study has found that Irish ten-year-olds are less happy in school and are more likely to feel that they do not "belong", compared to children in other countries.
The study compared children in fourth class in Ireland with their peers internationally.
The Educational Research Centre study is part of a major international project comparing school systems in up to 60 countries.
It found children in Ireland twice as likely to not like school compared to the international average.
Boys are even more likely to be unhappy in school.
A higher proportion of teachers in Ireland also say they feel pupils are not getting enough sleep and that this is affecting their schoolwork.
The authors of the report say this is an issue of particular concern.
The report, National Schools, International Contexts, finds that bullying is less of a problem in Ireland compared to many other countries.
But it finds that boys in single-sex schools are more likely to be bullied.
Of all the countries surveyed, Irish primary schools are worse than any other when it comes to communicating information regarding children's academic progress to parents.
On the teaching of science, the study finds below average levels of confidence among teachers in teaching the subject.
It also finds Irish trainee teachers not spending enough time on science at college.
Over a three-year teacher training course it found just between 12 and 40 hours in total was spent on science.
The study found Irish ten-year-olds spend far less time studying science in school - 7%, compared to an international average of 10%.
They spend more time on religion than any other country except Israel.
Irish pupils also spend less time on physical education, just 4%, than any other country.
The study finds that teachers in Ireland are younger than in most other countries and that 40% of teachers in Ireland are under the age of 30.
That compares to just 14% internationally.
While teachers in Ireland report high levels of job satisfaction they are far less likely to collaborate than teachers elsewhere.
One quarter of pupils in Ireland are taught by teachers who say they never or almost never discuss teaching with colleagues.
Only four countries fare worse than Ireland in this regard - Malta, Morocco, Tunisia and Yemen.