We examined the influence of teachers' use of instructional time on students' learning within the context of a randomized controlled trial investigating the effects of a content-area reading comprehension intervention. Participants were 8th grade social studies teachers who had their classes randomly assigned to either Promoting Acceleration of Comprehension and Content through Text (PACT) or business-as-usual (BAU). In both conditions, the same social studies content was the focus of instruction. Thirty-five 8th grade teachers (18 female, 17 male) audio-record instruction in both PACT and BAU classes for the duration of the 6-8 week intervention. Instruction was coded on five dimensions: interactive instruction, teacher silence, noninstructional activities, video usage, and neutral class time. Social studies knowledge acquisition was measured amongst 2786 8th grade students. Findings indicated that teachers spent more time engaged in interactive instruction when delivering content-area instruction in PACT classrooms as compared to BAU classrooms. Further, instructional behaviors were significantly related to changes in content knowledge acquisition in the BAU classes. In the treatment condition, teachers' instructional behaviors were not significantly related to changes in content acquisition, except for noninstructional activities and non-content related video, which both had negative effects. Our findings suggest that while interactive instructional time remains important, the instructional methods utilized during this time are equally (if not more) impactful on student achievement.