Motivation to learn foreign languages is a significant determinant of successful language acquisition. The subject has been widely researched in the past, and since the early 1990s a great deal of empirical research related to the classroom environment has been proposed to expand theory into everyday classroom practice. I present an empirical, longitudinal (3-year) study to explore the relationship between and changes in foreign language learning motivation, learning motivation and self-concept in the 5th, 6th and 8th forms of elementary school. The same tests (Kozéki-Entwistle's Learning Motivation Questionnaire, the Tennessee Self-Concept Scale, and Clément, Dörnyei and Noels' Foreign Language Learning Motivation questionnaire) were administered three times, so I was able to compare the results and draw conclusions about developmental tendencies. A strong correlation was found between motivational and self-esteem scores, and between learning and foreign language learning motivation subscales. It is necessary to highlight the importance of the Moral, Family and Social Self, which draws our attention to the family values and beliefs students are equipped with, when they enter the school. The significant decrease in motivation and self-esteem in the period under investigation focuses our attention on problems of adolescence, and challenges language teachers to establish a highly motivating classroom practice.