The present study investigated intraindividual variation in students' interest experience in 3 school subjects and the predictive power of perceived autonomy support and control. Participants were 261 students in 7th grade. After a survey of students' individual interests and other individual characteristics, repeated lesson-specific measures of students' interest experience and perceived autonomy support and control during instruction were obtained over a 3-week period. Hierarchical linear modeling showed 36%-45% of the variance to be located at the within-student level. Moreover, perceived autonomy support and control during lessons, as well as individual interest, predicted students' interest experience in the classroom. (Contains 3 tables and 3 footnotes.)