A Newsround survey has found that nearly 70% of children are put off using their school toilets because they're in such a state.
We also asked what the main reason was for not visiting the school loos - and 43% of you said that they were dirty.
The survey of 370 kids in the UK, aged 10 to 14, also found that a quarter of pupils do not use the toilets because the locks don't work.
Only 13% of those asked said there were no problems with their school loos.
Health experts are worried that if children don't go to the toilet when they need to and hold it in, they could end up constipated - bunged up - or with bladder infections.
The results of the survey also showed that 11% of children are stopped using the loos by teachers - although it may be that this is done sometimes to prevent bullying.
There were 12 children - that's 3% - who didn't use the toilets because they were scared of being bullied and five pupils who didn't use the bogs because they were dark.