Researchers from the University of Virginia looked at transcripts and data for more than 18,000 tenth grade students nationwide.
Their findings show more homework assignments didn't translate into better grades.
According to the Daily Mail newspaper, the study found homework doesn't necessarily help children to get better grades, but may help them get better standardized test scores.
The paper wrote: Co-author Robert Tai, associate professor of science education at the university's Curry School of Education, said: 'The more time students spend on homework, it's not clear that they are getting better grades or better test scores.
'What we are concerned with is that homework is just being assigned rather than being used to integrate what's going on in the classroom.'