Student teachers' desire to learn is affected by a variety of motivational factors. In this study, the effect of some internal and external variables on Academic Intrinsic Motivation (AIM) was explored. First, the validity and reliability of the scale of AIM was determined, then the effect on AIM of variables such as grade levels, academic grade point averages, learning environments, and the desire to be a teacher were examined. The research was carried out with 780 student teachers in the fall semester of 2012-13, and a survey model was used for the study. The AIM scale and personal information forms were used to collect data. In order to determine the construct validity of the AIM scale, item analysis, as well as exploratory and confirmatory factor analysis methods, were employed, respectively. In the second phase of the study, descriptive statistics, independent sample t-tests, and one-way analysis of variance (ANOVA) techniques were used for the independent variables. Also, logistic regression analysis was used to compare the variable of student teachers' desire to be a teacher and their AIM. Results revealed that the AIM scale was comprised of four sub-scales, including a need for achievement, social acceptance, a fear of failure, and mastery. Additionally, the scale was found to be valid and reliable. Furthermore, significant differences were found between student teachers' AIM and their academic grade point averages, grade levels and their desires to be a teacher. Finally, the study found that student teachers who have medium and high-level AIM have a high likelihood of practicing teaching as a profession in the future.