This thesis investigates Turkish students’ autonomous and controlled motivation in preparatory programs for English language and their correlates. Specifically, the study examined (a) to what extent preparatory school students’ autonomous and controlled motivation for their English courses in preparatory school (specific level) can be predicted by their motivations to study for their disciplinary courses in a university department (contextual level). Also, this research examined (b) the relation between autonomous and controlled motivation for English courses and students’ academic achievement and vitality in preparatory English classes. In order to analyze the relations between the variables, a cross-sectional correlational research design was applied. The study was conducted in fourteen universities in Turkey with 121 participants. (Mean age = 20.04; SD = 1,319). The results of the two-step hierarchical regression analyses revealed that students’ autonomous or controlled motivation at a specific level (English classes) was significantly predicted by their autonomous or controlled motivation at a contextual level (disciplinary courses). Also, the regression analysis indicated that specific controlled motivation of the participants was high when they prolonged their studies in preparatory school in addition to a low level of proficiency in English. On the other hand, the achievement scores were negatively and positively associated with specific controlled and autonomous motivation, respectively. Finally, the findings revealed that vitality was positively related with specific autonomous motivation, while both vitality and achievement was lower both for students with low level of proficiency in English and for students who failed to complete English studies in their first year.