In present-day psychological literature there is a number of various motivation theories aiming to clarify the basic principles of the motivation of human behaviour. A useful application of these theories in educational psychology, however, has not yet been adequately elaborated. Therefore it is the aim of this article to give at least a partial synthesis of some of the latest and some of the traditional findings in the field of the motivation of school performance so that they can be used both in theory of education and in school practice. Motivation factors influencing the pupil’s school performance are classified here from the viewpoint of internal and external conditions under which the school performance takes place. The author goes on to mention briefly some negative motivation influences which have an adverse effect on the pupil’s school performance. The basic internal motivation variables influencing the pupil’s school performance are considered to be the needs, especially cognitive, social and achievement. External conditions in this phase are reduced to school marks and rating, rewards and punishments. The concluding part of the article deals with frustration, psychological conflict and excessive motivation. Although this is an obvious reduction of a broad scale of motivation influences, this classification enables us to penetrate more deeply into the problems involved and thereby to adopt a more differentiated approach to individual pupils.