This article deals with the structure of intellectual capability in connection with the utilization of the mental capacities of pupils and the possibility of increasing the efficiency of, and of optimizing educational woric Intellectual capability is one of the factors that have an important place in the educational process and influence the level of school results. The article mentions some of the main results of the research which was focused on questions concerning the types of intellectual ability and the possibilities of their being used in school work. The author aims to present a view where the broad complex of problems involved in school success is supplemented with the role played by the specificity of the structure of intellectual ability. Besides factors outside the sphere of abilities, it is the intellectual ability — not only its the global level (which is, for the present, predominantly used in research work), but especially the type of its structure — that is the very factor which has an effect on the level of the school results of pupils. The starting point is the assumption that in school work use is made of those capabilities whose structure is more in line with the structure of the activities required. The results draw attention to the fact that worse results in school work may not always be caused only by a lower level of intellectual ability or by factors outside the ability sphere, but also by the clear-cut specificity, the type of intellectual ability. This approach to the traditional problem of psychology of capabilities indicates further possibilities in disclosing reserves in pupils’ mental capacities.