New research has found that only 4% of parents know that there are tests in five out of seven primary school years.
According to the report 74% of parents think children are under too much pressure.
A video has been released by the Brighton-based campaign group More than a Score.
It aims to raise awareness that primary school children are now among the most tested in the world.
The amount and type of formal testing is something that concerns many parents such as mum of three Viv Mudie from Southwick near Shoreham.
"At least two of my children have found it really stressful and become more anxious and worried - they constantly going on about not being good enough or they are going to fail things which seems too much when they are only 8, 9, 10, 11."
Parents think tests have negative impact on wellbeing
Say it is unfair to measure schools by formal tests
Parents think there is too much primary testing
Michele Lawrie is the headteacher at St. Peter's Community Primary School in Portslade.
She says in her opinion the testing is too much for primary children.
"We trust teachers to administer these tests in an appropriate way and so they should not be a source of stress for children."
Many parents say they are not against testing per se but some worry that with testing so heavily focused on numeracy and literacy, creativity is being lost and squeezed out and it is time for a rethink.