The families spoke out after qualified instructors trained to support pupils with severe visual, hearing and communication difficulties were cut from a number of special schools in the primary sector.
The group of parents were told by council officials at a meeting last May that the staff, who have been moved to the secondary sector, would be replaced.
However, the parents from Broomlea, Langlands and Howford schools say that, apart from one or two members of staff, no replacements have been provided.
But Glasgow City Council argues that, under the staffing formula applied to schools, there are enough teachers and support staff to cater for the number of pupils.
It has also been suggested that previous staffing levels at some of the schools were higher than in others and that the changes were driven by a need to spread support more evenly.
Catherine Dooley, chairwoman of the parent council of Broomlea, in Possil, said the situation was a constant source of worry and called for more permanent staff to be installed.
She said: "The loss of staff has led directly to a decline in the quality of teaching and support for our children in these schools.
"Broomlea has lost five of its more senior staff and with them goes years of experience in the special needs sector that can never be replaced.
"The staff at Broomlea are facing unimaginable stress and it's no longer a place where we feel our children can learn."
Sarah Nicolson, a parent with a child at Langlands, said she had withdrawn her child from the school this term because of the lack of support staff.
She said: "I wasn't happy with the size of the class my son was in after we lost the support staff and it is something they need to sort out as a matter of urgency. The quality of what is on offer is not the same as it was before and no-one seems to be listening to our concerns."
The council said extra staff would be provided where a specific need arose, with new recruits currently having disclosure checks.
A Glasgow City Council spokeswoman said: "The specialised needs of every pupil are being met by the dedicated staff at the schools.
"The number of staff is based on the assessed needs of each individual child and headteachers are fully involved in that assessment.
"Because the number of support staff is based on individual needs it is not unusual to have more or less support staff each year or for support staff numbers to change during the year. We recognise the need to be flexible and that is why they have been given additional staff in the past."
The spokeswoman said it was always the intention to recruit staff later in the term rather than at the start of the school year.