Meeting the basic educational needs of children with Down syndrome and students with developing disabilities is a topic that is being increasingly explored and discussed in the pedagogical and wider, social context. Understanding the clinical characteristics of children with Down syndrome is the basis for understanding and accepting their special educational needs. Satisfying their special needs is the duty of every participant in the educational practice, because of the right of every individual to equal education and the realization of their full potential, and for the creation of a society that accepts and nurtures differences. The topic of the paper is inclusion of children with Down syndrome in regular elementary schools. One of the main goals of the paper is to answer questions that are important for the successful inclusion of children with Down syndrome in elementary schools in the Republic of Croatia, taking into account the educational needs of children with Down syndrome, the current situation in Croatian education system and the preconditions that are important for a successful inclusive practice. At the very beginning, the paper discuses Down syndrome as a genetic disorder, clinical characteristics and educational opportunities for children with Down syndrome. Furthermore, the paper deals with full educational inclusion of children with disabilities in regular elementary schools, principles and methods of education in such an inclusive school, possible models of schooling of children with special educational needs and legal frameworks that regulate contemporary inclusive theory and practice. Since the competencies of every participant of the educational practice are of great importance for a successful inclusive practice, the paper lists the key competencies that a classroom teachers should have and the ability to educate classroom teachers to work with children with special needs in the Republic of Croatia.