This article deals with some questions concerning the relationship of groups of pupils and pioneers, especially the problem of the primary group and its formation at school and in the Pioneer Organization, then the problem of homogeneity or heterogeneity of members’ age in the Pioneer group, the problem of co-education in Pioneer sections and the problems involved in the relationship of a class of Pupils and a section of Pioneers. The bulk of the work of Pioneers is carried on in Pioneer teams. The Pioneer team is the basic group in the Pioneer Organization. It should not be set up formally, but it should respect the spontaneous bonds of friendship between individual members, provided they are positively motivated and appropriately directed by the section leader and the elected organs of the Pioneer section. In placing pioneers into individual teams the decisive factors are: common activities and a common goal, their quality being evaluated from the point of view of society as a whole, provided personal interests are sufficiently respected. In that case the formation of the group will not get bogged down at the level of the basic group, but pre-requisites are created for the formation of a higher group characterized mainly by the fact that its interests and objectives result not from the simple contact between individual members of the group, but from a deeper social synthesis and therefore are of greater value from the national point of view. A group made up of pupils in a class cannot be identified with a group made up of members of a Pioneer section, but one cannot unequivocally deny the existence of such Pioneer sections whose members belong to one and the same class at school, because the school provides the pre-requisites for a successful operation of such sections. Above all, it is a question of personnel, technical and organizational conditions of the operation of Pioneer sections.