Pupils came up with the idea of the parking notices after being worried about crossing roads near Hillside Primary School in Bradwell, Norfolk.
Head teacher, Simon Minter said safety was at risk and despite a 30mph speed limit outside the school, there had been "several near misses".
Children issued 12 of the unofficial tickets to drivers of offending cars.
Toby, who is on the school council, came up with the idea: "A lot of children are starting to walk to school and a lot of parents are parking where they're not meant to be."
One parent who parked on a bus stop outside the school said she was late and knew a bus was not expected for another 20 minutes, but added she "would never park there again."
The children's actions were endorsed by many parents dropping off children.
"I really agree with them getting tickets. I think it's disgusting that they think they can park where they like and put kids in danger," said one parent.
Mr Minter said there was parking nearby even if that would involve a short walk.
"We've got some incredibly supportive parents but many don't realise the impact of their actions en-masse.
"We provide year five and six with as much independence as we can. If they don't see approaching traffic because of cars parked where they shouldn't be, they put themselves in danger," he said.
The school has 209 pupils and the head said "a greater proportion could walk to school" which would be a benefit given that "fitness is an issue in the area".
He explained the catchment had seen a 7% to 12% rise in obesity levels among children.
The school said it planned to run the ticketing exercise regularly.
Parents who park or drive badly near a village school have received 'parking tickets' issued by pupils.