The authors base this study on archival research on the plan and program of schools for children with developmental disabilities in the People's / Socialist Republic of Croatia when that type of school was called a "special school". The plan and program are followed in the development cycle from the independent operation of those schools in the 60s of the 20th century until the collapse of the SFRY and the full or partial adoption of the program by students according to individual possibilities. In the description of the processing of teaching materials in individual classes, they deal with individual work and work with the whole class. They monitor the adoption of teaching materials by subjects in lower and higher grades and evaluation, which was carried out according to their psycho-physical capabilities. In particular, the authors deal with the meaning of work education, which, according to the plan and program of those schools, was given great importance, namely in the distinct activity of the students, the development of the senses, fine motor skills, handling of tools and connection with other subjects. In the concluding part, they show in individual school years the greater or lesser success of students in mastering the curriculum.