There is a great interest for alternatives in pedagogy and need is shown foe their application in early and preschool upbringing and education. Kindergartens and schools following concepts of their way of work are opened and staff is being eduacted to successfully implement their ideas in educational work. Marie Montessori pedagogy is one of the leading alternative in world. Her pedagogy conception is acting over long period of years and it has been successful in work with children which have development difficulties. Aim of this graduate thesis is to clarify Montessori pedagogy and her positive influence on education of children with development difficulties. Besides mentioned, theoretical introduction in education of children with development difficulties will be given and it will be described how these children were viewed throughout history and beginnings of their education as well. Aim of research was to inspect how and in which way Montessori pedagogy influence on education of children with development difficulties. Important elements of Montessori pedagogy which contribute overall development of children with development difficulties will be presented as well. Besides educational work, benefits of mixed groups will be explained and terms of inclusion and integration will be explained more in detail. Progress of one child with development difficulties will be described based on systematic observation.