Pupils’ motivation for instrument lessons is an important factor in the development of young musicians, which often causes various doubts and difficulties for instrument teachers. The topic of this diploma thesis is to identify which factors influence a pupil’s motivation in instrument lessons, and to what degree. In the theoretical part of the thesis, motivation is depicted as a psychological term and the concept of instrument lessons in Croatia is described. The thesis examines the process of acquiring musicianship skills, motivation in instrument lessons and various factors that have an impact on the motivation in instrument lessons. As a part of the thesis, research was conducted in three music schools (the Music School in Novska, the Music School at Marija Bistrica, and the music department of the Elementary School of Franjo Horvat Kiš in Lobor) in the Republic of Croatia. The anonymous survey included 104 respondents from the third grade of primary music school to the third grade of secondary music school. The respondents expressed their opinions on motivation in instrument lessons and the factors that affect it. The results show that there are not any significant differences in opinions regarding attending music schools, the amount of support pupils receive, the student-teacher relationship in instrument lessons, the amount of practice and motivation with regard to gender, parental musical education and parental involvement in music. The results reveal that the students' willingness is the main reason for enrolling and attending music school. The results demonstrate that students like to practice, and most of them do so to develop their playing skills. Pupils believe that they receive the necessary support from their parents for playing musical instruments, and their friends from general education schools appreciate their musical skills. The results indicate that the majority of pupils are satisfied with their relationship with the instrument teacher and that the instrument teacher knows how to motivate them.