In this study, reading motivations of university students enrolled in the preparatory school of a private university in Ankara were investigated. Firstly, the factors that constitute the reading motivation in Turkish and English were explored using a questionnaire which was adapted from the related literature. Then, the relationship between L1 reading motivation and L2 reading motivation was investigated. Next, the relationship between L1 and L2 reading motivation and L2 reading achievement was analyzed separately. In addition to the nature of reading motivation, students&rsquo / text selections and reading habits (how often, how long and how many pages they read) were included in the analysis. Finally, preparatory school instructors&rsquo / and students&rsquo / perceptions of reading motivation and the factors influencing it were scrutinized. In order to address the issues stated above, both qualitative and quantitative data were collected with the help of a questionnaire and semi-structured face-to-face interviews. A total of 273 questionnaires were collected from the students in two instruction levels. In addition, fifteen teachers and eight students were interviewed. The findings indicated that there is a slight relationship between L1 reading motivation and l2 reading motivation. Secondly, L1 reading motivation and behaviors made no significant contribution to L2 reading achievement. However, L2 reading motivation and behaviors were found to be significant contributors of L2 reading achievement. Among these, while the factor anxiety was found to be a significant factor in pre-intermediate level and the factor comfort was the significant factor in the upper-intermediate level. Among the text selections, students prefer to read, transactional texts had a positive correlation with L2 reading achievement. Finally, time students spend reading in English was found to be a significant contributor. Apart from the questionnaire data, the teacher interviews revealed that several other factors affect students&rsquo / reading motivation and their reading comprehension such as the classroom-specific motivational variables and the family and educational backgrounds of the students.