The Scottish Disability Equality Forum says businesses have to do more for disabled employees or customers than schools do.
Research carried out by SDEF looked at 60 state and independent providers of primary and secondary schooling. Just two of 60 were able to provide an accessibility strategy that met 2002 Education Act requirements.
Susan Grasekamp, CEO of SDEF, said: "It's astonishing that, as equalities law stands, a bank is required to modify a branch for a disabled employee or customer, but a school does not have to adapt their building for a disabled pupil.
"Scottish legislation, which should be increasing access for disabled pupils is being largely ignored. We want to see education providers, Education Scotland and the Scottish Government taking this seriously."