Only the accommodation and facilities at Campsie View School in Lenzie fall below top ranking - and they are described as good.
Inspectors praise the "outstanding" leadership of Carol Bowie, the school's head. Ms Bowie has been invited to Downing Street next month to meet the Prime Minister as part of a celebration of people who have made an outstanding contribution to pupils with special educational needs.
As the authority is quick to point out, the commendation comes only two weeks after HMI criticised the leadership in one in five special schools.
Inspectors also urged special schools to broaden their curriculum. At Campsie View, the quality of the curriculum for all 62 children aged 2-19 is said to be very good, along with pupils' achievements. Some 65 per cent of lessons won the highest grading.
"Pupils' experience was much enhanced by a rich programme of visits, excursions and extracurricular experiences," HMI states.
Ms Bowie said: "We do a very professional job and the report is particularly pleasing as it is always encouraging to have your efforts recognised."