Tonnes of paper, plastic and glass from schools is being dumped in landfill sites each year.
Schools in Brighton and Hove are not provided with recycling boxes and a regular collection by the local authority.
Brighton and Hove City Council says schools are given a "sufficient budget" to pay for waste disposal as well as overheads, salaries, books and new equipment.
Headteachers claim they don't have enough money to provide recycling services. As a result, rubbish is being dumped instead of recycled.
They are now urging city council leaders to draw up a recycling plan for the 76 primary and secondary schools across Brighton and Hove to prevent unnecessary waste going to landfill.
It comes as schools across the city are teaching children how to be environmentally-friendly with lessons about recycling and sustainability.
Michael Jee, the headteacher at Aldrington Primary School, Hove, said: "We would love to spend the money we are given on recycling but we simply can't afford it. Schools are always strapped for cash.
"Utility bills have doubled in the last year so it's harder than ever to stick to the budget.
"If the city council can stop at every house and collect residents' recycling they should be able to stop at each of the schools."
Mr Jee said Aldrington recycled food scraps on its allotment, sent old shoes and clothes to charities and often took car loads of dated furniture to be recycled.
He added: "The main problem is paper. Even though we are careful, we get through between 15 and 20 bin bags of it each week. It's not practical for us to get rid of that properly.
"We are trying to teach pupils about the importance of recycling and sustainability but not giving them the practical means to do it. It's a very mixed message."
Stuart McLaughlin, headteacher at Falmer High School in Brighton, said the school was forced to pay a private company to collect and shred all its waste paper.
He said: "We want to encourage recycling but it can be very expensive if we have to pay ourselves. In other education authorities the council has set up a collection service. I think it would be really helpful and send a very positive message if they did that here."
Some schools have large paper bins provided by the city council but there is no provision for cardboard, plastics or glass.
Green city councillor Keith Taylor said: "It's totally wrong that schools don't have a recycling service. It's an appalling example to pupils. I would like to see a way found for a comprehensive recycling scheme to be rolled out across all the schools."
Christine Wiltshire, waste campaigner for the Brighton and Hove branch of Friends of the Earth, said more should be done to help schools recycle.
She said: "Most schools want to recycle. Teachers are keen to do what they can but they don't seem to have the support to make it happen.
"There isn't a strong enough message being sent out to children about the need to recycle."
A city council spokeswoman said the city council was in the early stages of setting up a new private contractor deal for recycling at public buildings including schools.
She said: "Schools have a delegated budget for waste disposal and it's up to the individual school how they elect to get rid of their rubbish and recycling.
"We work extensively with schools to encourage recycling both at home, at school and in the community."
A West Sussex County Council spokesman said 290 schools were included in a centralised rubbish collection contract with Biffa. The county council is putting out to tender for a new contractor to start from October which will include a recycling service for schools.
East Sussex County Council is considering similar action. A spokeswoman said 120 of the 172 schools surveyed last September wanted a recycling service. Now the council is gathering information on recycling produced by each school.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article