The authors extend previous work on students' perceptions of teachers' autonomy-enhancing and autonomy-suppressing behaviors in relation to students' engagement to a more situated context (i.e., two Grade 4 science instructional conditions instead of school in general) and a linguistically diverse population (i.e., Hispanic students). They also examine perceptions of teachers' behaviors in relation to students' reading motivation. Students' perceptions of teacher behaviors predicted students' feelings toward and engagement in science but relations differed from Assor, Kaplan, and Roth's (2002) work. Reading motivation was most consistently predicted by perceptions of allowing criticism and independent thinking. Perceptions of task and topic relevance did not significantly predict students' engagement, or motivation when included with the other autonomy-affecting behaviors. These relations were found for all students in the sample, irrespective of language minority status or science instructional condition. (Contains 4 tables.)